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2014-04-07percpu: add preemption checks to __this_cpu opsChristoph Lameter
We define a check function in order to avoid trouble with the include files. Then the higher level __this_cpu macros are modified to invoke the preemption check. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Tested-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07vmstat: use raw_cpu_ops to avoid false positives on preemption checksChristoph Lameter
vm counters are allowed to be racy. Use raw_cpu_ops to avoid the local_irq_disable overhead and to avoid preemption checks which will be added to the __this_cpu operations. [akpm@linux-foundation.org: Add comment. Again.] Signed-off-by: Christoph Lameter <cl@linux.com> Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dave Chinner <dchinner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: use raw_cpu ops for determining current NUMA nodeChristoph Lameter
With the preempt checking logic for __this_cpu_ops we will get false positives from locations in the code that use numa_node_id. Before the __this_cpu ops where introduced there were no checks for preemption present either. smp_raw_processor_id() was used. See http://www.spinics.net/lists/linux-numa/msg00641.html Therefore we need to use raw_cpu_read here to avoid false postives. Note that this issue has been discussed in prior years. If the process changes nodes after retrieving the current numa node then that is acceptable since most uses of numa_node etc are for optimization and not for correctness. There were suggestions to implement a raw_numa_node_id in order to do preempt checks for numa_node_id as well. But I think we better defer that to another patch since that would mean investigating how numa_node_id() is used throughout the kernel which would increase the scope of this patchset significantly. After all preemption was never checked before when numa_node_id() was used. Some sample traces: __this_cpu_read operation in preemptible [00000000] code: login/1456 caller is __this_cpu_preempt_check+0x2b/0x2d CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3-dirty #185 Call Trace: dump_stack+0x4e/0x82 check_preemption_disabled+0xc5/0xe0 __this_cpu_preempt_check+0x2b/0x2d get_task_policy+0x1d/0x49 get_vma_policy+0x14/0x76 alloc_pages_vma+0x35/0xff handle_mm_fault+0x290/0x73b __do_page_fault+0x3fe/0x44d do_page_fault+0x9/0xc page_fault+0x22/0x30 generic_file_aio_read+0x38e/0x624 do_sync_read+0x54/0x73 vfs_read+0x9d/0x12a SyS_read+0x47/0x7e cstar_dispatch+0x7/0x23 caller is __this_cpu_preempt_check+0x2b/0x2d CPU: 0 PID: 1456 Comm: login Not tainted 3.12.0-rc4-cl-00062-g2fe80d3-dirty #185 Call Trace: dump_stack+0x4e/0x82 check_preemption_disabled+0xc5/0xe0 __this_cpu_preempt_check+0x2b/0x2d alloc_pages_current+0x8f/0xbc __page_cache_alloc+0xb/0xd __do_page_cache_readahead+0xf4/0x219 ra_submit+0x1c/0x20 ondemand_readahead+0x28c/0x2b4 page_cache_sync_readahead+0x38/0x3a generic_file_aio_read+0x261/0x624 do_sync_read+0x54/0x73 vfs_read+0x9d/0x12a SyS_read+0x47/0x7e cstar_dispatch+0x7/0x23 Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Alex Shi <alex.shi@intel.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07percpu: add raw_cpu_opsChristoph Lameter
The kernel has never been audited to ensure that this_cpu operations are consistently used throughout the kernel. The code generated in many places can be improved through the use of this_cpu operations (which uses a segment register for relocation of per cpu offsets instead of performing address calculations). The patch set also addresses various consistency issues in general with the per cpu macros. A. The semantics of __this_cpu_ptr() differs from this_cpu_ptr only because checks are skipped. This is typically shown through a raw_ prefix. So this patch set changes the places where __this_cpu_ptr() is used to raw_cpu_ptr(). B. There has been the long term wish by some that __this_cpu operations would check for preemption. However, there are cases where preemption checks need to be skipped. This patch set adds raw_cpu operations that do not check for preemption and then adds preemption checks to the __this_cpu operations. C. The use of __get_cpu_var is always a reference to a percpu variable that can also be handled via a this_cpu operation. This patch set replaces all uses of __get_cpu_var with this_cpu operations. D. We can then use this_cpu RMW operations in various places replacing sequences of instructions by a single one. E. The use of this_cpu operations throughout will allow other arches than x86 to implement optimized references and RMV operations to work with per cpu local data. F. The use of this_cpu operations opens up the possibility to further optimize code that relies on synchronization through per cpu data. The patch set works in a couple of stages: I. Patch 1 adds the additional raw_cpu operations and raw_cpu_ptr(). Also converts the existing __this_cpu_xx_# primitive in the x86 code to raw_cpu_xx_#. II. Patch 2-4 use the raw_cpu operations in places that would give us false positives once they are enabled. III. Patch 5 adds preemption checks to __this_cpu operations to allow checking if preemption is properly disabled when these functions are used. IV. Patches 6-20 are patches that simply replace uses of __get_cpu_var with this_cpu_ptr. They do not depend on any changes to the percpu code. No preemption tests are skipped if they are applied. V. Patches 21-46 are conversion patches that use this_cpu operations in various kernel subsystems/drivers or arch code. VI. Patches 47/48 (not included in this series) remove no longer used functions (__this_cpu_ptr and __get_cpu_var). These should only be applied after all the conversion patches have made it and after we have done additional passes through the kernel to ensure that none of the uses of these functions remain. This patch (of 46): The patches following this one will add preemption checks to __this_cpu ops so we need to have an alternative way to use this_cpu operations without preemption checks. raw_cpu_ops will be the basis for all other ops since these will be the operations that do not implement any checks. Primitive operations are renamed by this patch from __this_cpu_xxx to raw_cpu_xxxx. Also change the uses of the x86 percpu primitives in preempt.h. These depend directly on asm/percpu.h (header #include nesting issue). Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Christoph Lameter <cl@linux.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Alex Shi <alex.shi@intel.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Bryan Wu <cooloney@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: David Daney <david.daney@cavium.com> Cc: David Miller <davem@davemloft.net> Cc: David S. Miller <davem@davemloft.net> Cc: Dimitri Sivanich <sivanich@sgi.com> Cc: Dipankar Sarma <dipankar@in.ibm.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: H. Peter Anvin <hpa@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Hedi Berriche <hedi@sgi.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: John Stultz <john.stultz@linaro.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Mike Travis <travis@sgi.com> Cc: Neil Brown <neilb@suse.de> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Robert Richter <rric@kernel.org> Cc: Russell King <linux@arm.linux.org.uk> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07slub: rework sysfs layout for memcg cachesVladimir Davydov
Currently, we try to arrange sysfs entries for memcg caches in the same manner as for global caches. Apart from turning /sys/kernel/slab into a mess when there are a lot of kmem-active memcgs created, it actually does not work properly - we won't create more than one link to a memcg cache in case its parent is merged with another cache. For instance, if A is a root cache merged with another root cache B, we will have the following sysfs setup: X A -> X B -> X where X is some unique id (see create_unique_id()). Now if memcgs M and N start to allocate from cache A (or B, which is the same), we will get: X X:M X:N A -> X B -> X A:M -> X:M A:N -> X:N Since B is an alias for A, we won't get entries B:M and B:N, which is confusing. It is more logical to have entries for memcg caches under the corresponding root cache's sysfs directory. This would allow us to keep sysfs layout clean, and avoid such inconsistencies like one described above. This patch does the trick. It creates a "cgroup" kset in each root cache kobject to keep its children caches there. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07memcg, slab: do not destroy children caches if parent has aliasesVladimir Davydov
Currently we destroy children caches at the very beginning of kmem_cache_destroy(). This is wrong, because the root cache will not necessarily be destroyed in the end - if it has aliases (refcount > 0), kmem_cache_destroy() will simply decrement its refcount and return. In this case, at best we will get a bunch of warnings in dmesg, like this one: kmem_cache_destroy kmalloc-32:0: Slab cache still has objects CPU: 1 PID: 7139 Comm: modprobe Tainted: G B W 3.13.0+ #117 Call Trace: dump_stack+0x49/0x5b kmem_cache_destroy+0xdf/0xf0 kmem_cache_destroy_memcg_children+0x97/0xc0 kmem_cache_destroy+0xf/0xf0 xfs_mru_cache_uninit+0x21/0x30 [xfs] exit_xfs_fs+0x2e/0xc44 [xfs] SyS_delete_module+0x198/0x1f0 system_call_fastpath+0x16/0x1b At worst - if kmem_cache_destroy() will race with an allocation from a memcg cache - the kernel will panic. This patch fixes this by moving children caches destruction after the check if the cache has aliases. Plus, it forbids destroying a root cache if it still has children caches, because each children cache keeps a reference to its parent. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07memcg, slab: separate memcg vs root cache creation pathsVladimir Davydov
Memcg-awareness turned kmem_cache_create() into a dirty interweaving of memcg-only and except-for-memcg calls. To clean this up, let's move the code responsible for memcg cache creation to a separate function. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07memcg, slab: cleanup memcg cache creationVladimir Davydov
This patch cleans up the memcg cache creation path as follows: - Move memcg cache name creation to a separate function to be called from kmem_cache_create_memcg(). This allows us to get rid of the mutex protecting the temporary buffer used for the name formatting, because the whole cache creation path is protected by the slab_mutex. - Get rid of memcg_create_kmem_cache(). This function serves as a proxy to kmem_cache_create_memcg(). After separating the cache name creation path, it would be reduced to a function call, so let's inline it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Glauber Costa <glommer@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07Kconfig: rename HAS_IOPORT to HAS_IOPORT_MAPUwe Kleine-König
If the renamed symbol is defined lib/iomap.c implements ioport_map and ioport_unmap and currently (nearly) all platforms define the port accessor functions outb/inb and friend unconditionally. So HAS_IOPORT_MAP is the better name for this. Consequently NO_IOPORT is renamed to NO_IOPORT_MAP. The motivation for this change is to reintroduce a symbol HAS_IOPORT that signals if outb/int et al are available. I will address that at least one merge window later though to keep surprises to a minimum and catch new introductions of (HAS|NO)_IOPORT. The changes in this commit were done using: $ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/' Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07bug: Make BUG() always stop the machineJosh Triplett
When !CONFIG_BUG and !HAVE_ARCH_BUG, define the generic BUG() as an infinite loop rather than a no-op. This avoids undefined behavior if execution ever actually reaches BUG(), and avoids warnings about code after BUG() (such as on non-void functions calling BUG() and then not returning). bloat-o-meter results: add/remove: 0/0 grow/shrink: 43/10 up/down: 235/-98 (137) function old new delta umount_collect 119 138 +19 notify_change 306 324 +18 xstate_enable_boot_cpu 252 269 +17 kunmap 54 70 +16 balloon_page_dequeue 112 126 +14 mm_take_all_locks 223 233 +10 list_lru_walk_node 143 152 +9 vma_adjust 1059 1067 +8 pcpu_setup_first_chunk 1130 1138 +8 mm_drop_all_locks 143 151 +8 ns_capable 55 62 +7 anon_transport_class_unregister 8 15 +7 srcu_init_notifier_head 35 41 +6 shrink_dcache_for_umount 174 180 +6 kunmap_high 99 105 +6 end_page_writeback 43 49 +6 do_exit 1339 1345 +6 __kfifo_dma_out_prepare_r 86 92 +6 __kfifo_dma_in_prepare_r 90 96 +6 fixup_user_fault 120 125 +5 repair_env_string 73 77 +4 read_cache_pages_invalidate_page 56 60 +4 isolate_lru_pages.isra 142 146 +4 do_notify_parent_cldstop 255 259 +4 cpu_init 370 374 +4 utimes_common 270 272 +2 tasklet_hi_action 91 93 +2 tasklet_action 91 93 +2 set_pte_vaddr 46 48 +2 find_get_pages_tag 202 204 +2 early_iounmap 185 187 +2 __native_set_fixmap 36 38 +2 __get_user_pages 822 824 +2 __early_ioremap 299 301 +2 yield_task_stop 1 2 +1 tick_resume 37 38 +1 switched_to_stop 1 2 +1 switched_to_idle 1 2 +1 prio_changed_stop 1 2 +1 prio_changed_idle 1 2 +1 pm_qos_power_read 111 112 +1 arch_cpu_idle_dead 1 2 +1 __insert_vmap_area 140 141 +1 sys_renameat 614 612 -2 mm_fault_error 297 295 -2 SyS_renameat 614 612 -2 sys_linkat 416 413 -3 SyS_linkat 416 413 -3 chmod_common 129 122 -7 proc_cap_handler 240 225 -15 __schedule 849 831 -18 sys_madvise 1077 1054 -23 SyS_madvise 1077 1054 -23 Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07bug: when !CONFIG_BUG, make WARN call no_printk to check format and argsJosh Triplett
The stub version of WARN for !CONFIG_BUG completely ignored its format string and subsequent arguments; make it check them instead, using no_printk. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reported-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07include/asm-generic/bug.h: style fix: s/while(0)/while (0)/Josh Triplett
Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07bug: when !CONFIG_BUG, simplify WARN_ON_ONCE and familyJosh Triplett
When !CONFIG_BUG, WARN_ON and family become simple passthroughs of their condition argument; however, WARN_ON_ONCE and family still have conditions and a boolean to detect one-time invocation, even though the warning they'd emit doesn't exist. Make the existing definitions conditional on CONFIG_BUG, and add definitions for !CONFIG_BUG that map to the passthrough versions of WARN and WARN_ON. This saves 4.4k on a minimized configuration (smaller than allnoconfig), and 20.6k with defconfig plus CONFIG_BUG=n. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07rapidio: rework device hierarchy and introduce mport class of devicesAlexandre Bounine
This patch removes an artificial RapidIO bus root device and establishes actual device hierarchy by providing reference to real parent devices. It also introduces device class for RapidIO controller devices (on-chip or an eternal bridge, known as "mport"). Existing implementation was sufficient for SoC-based platforms that have a single RapidIO controller. With introduction of devices using multiple RapidIO controllers and PCIe-to-RapidIO bridges the old scheme is very limiting or does not work at all. The implemented changes allow to properly reference platform's local RapidIO mport devices and provide device details needed for upper layers. This change to RapidIO device hierarchy does not break any known existing kernel or user space interfaces. Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com> Cc: Matt Porter <mporter@kernel.crashing.org> Cc: Li Yang <leoli@freescale.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com> Cc: Stef van Os <stef.van.os@prodrive-technologies.com> Cc: Jerry Jacobs <jerry.jacobs@prodrive-technologies.com> Cc: Arno Tiemersma <arno.tiemersma@prodrive-technologies.com> Cc: Rob Landley <rob@landley.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07idr: remove dead codeStephen Hemminger
Remove no longer used deprecated code, and make local functions static. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Jean Delvare <jdelvare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: Jeff Layton <jlayton@redhat.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: George Spelvin <linux@horizon.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07include/linux/crash_dump.h: add vmcore_cleanup() prototypeRashika Kheria
Eliminate the following warning in proc/vmcore.c: fs/proc/vmcore.c:1088:6: warning: no previous prototype for `vmcore_cleanup' [-Wmissing-prototypes] [akpm@linux-foundation.org: clean up powerpc, remove unneeded EXPORT_SYMBOL] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07wait: swap EXIT_ZOMBIE and EXIT_DEAD to hide EXIT_TRACE from user-spaceOleg Nesterov
get_task_state() uses the most significant bit to report the state to user-space, this means that EXIT_ZOMBIE->EXIT_TRACE->EXIT_DEAD transition can be noticed via /proc as Z -> X -> Z change. Note that this was possible even before EXIT_TRACE was introduced. This is not really bad but imho it make sense to hide EXIT_TRACE from user-space completely. So the patch simply swaps EXIT_ZOMBIE and EXIT_DEAD, this way EXIT_TRACE will be seen as EXIT_ZOMBIE by user-space. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Michal Schmidt <mschmidt@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07wait: introduce EXIT_TRACE to avoid the racy EXIT_DEAD->EXIT_ZOMBIE transitionOleg Nesterov
wait_task_zombie() first does EXIT_ZOMBIE->EXIT_DEAD transition and drops tasklist_lock. If this task is not the natural child and it is traced, we change its state back to EXIT_ZOMBIE for ->real_parent. The last transition is racy, this is even documented in 50b8d257486a "ptrace: partially fix the do_wait(WEXITED) vs EXIT_DEAD->EXIT_ZOMBIE race". wait_consider_task() tries to detect this transition and clear ->notask_error but we can't rely on ptrace_reparented(), debugger can exit and do ptrace_unlink() before its sub-thread sets EXIT_ZOMBIE. And there is another problem which were missed before: this transition can also race with reparent_leader() which doesn't reset >exit_signal if EXIT_DEAD, assuming that this task must be reaped by someone else. So the tracee can be re-parented with ->exit_signal != SIGCHLD, and if /sbin/init doesn't use __WALL it becomes unreapable. This was fixed by the previous commit, but it was the temporary hack. 1. Add the new exit_state, EXIT_TRACE. It means that the task is the traced zombie, debugger is going to detach and notify its natural parent. This new state is actually EXIT_ZOMBIE | EXIT_DEAD. This way we can avoid the changes in proc/kgdb code, get_task_state() still reports "X (dead)" in this case. Note: with or without this change userspace can see Z -> X -> Z transition. Not really bad, but probably makes sense to fix. 2. Change wait_task_zombie() to use EXIT_TRACE instead of EXIT_DEAD if we need to notify the ->real_parent. 3. Revert the previous hack in reparent_leader(), now that EXIT_DEAD is always the final state we can safely ignore such a task. 4. Change wait_consider_task() to check EXIT_TRACE separately and kill the racy and no longer needed ptrace_reparented() case. If ptrace == T an EXIT_TRACE thread should be simply ignored, the owner of this state is going to ptrace_unlink() this task. We can pretend that it was already removed from ->ptraced list. Otherwise we should skip this thread too but clear ->notask_error, we must be the natural parent and debugger is going to untrace and notify us. IOW, this doesn't differ from "EXIT_ZOMBIE && p->ptrace" even if the task was already untraced. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Jan Kratochvil <jan.kratochvil@redhat.com> Reported-by: Michal Schmidt <mschmidt@redhat.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Lennart Poettering <lpoetter@redhat.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07exec: kill bprm->tcomm[], simplify the "basename" logicOleg Nesterov
Starting from commit c4ad8f98bef7 ("execve: use 'struct filename *' for executable name passing") bprm->filename can not go away after flush_old_exec(), so we do not need to save the binary name in bprm->tcomm[] added by 96e02d158678 ("exec: fix use-after-free bug in setup_new_exec()"). And there was never need for filename_to_taskname-like code, we can simply do set_task_comm(kbasename(filename). This patch has to change set_task_comm() and trace_task_rename() to accept "const char *", but I think this change is also good. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07numa: use LAST_CPUPID_SHIFT to calculate LAST_CPUPID_MASKSrikar Dronamraju
LAST_CPUPID_MASK is calculated using LAST_CPUPID_WIDTH. However LAST_CPUPID_WIDTH itself can be 0. (when LAST_CPUPID_NOT_IN_PAGE_FLAGS is set). In such a case LAST_CPUPID_MASK turns out to be 0. But with recent commit 1ae71d0319: (mm: numa: bugfix for LAST_CPUPID_NOT_IN_PAGE_FLAGS) if LAST_CPUPID_MASK is 0, page_cpupid_xchg_last() and page_cpupid_reset_last() causes page->_last_cpupid to be set to 0. This causes performance regression. Its almost as if numa_balancing is off. Fix LAST_CPUPID_MASK by using LAST_CPUPID_SHIFT instead of LAST_CPUPID_WIDTH. Some performance numbers and perf stats with and without the fix. (3.14-rc6) ---------- numa01 Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa01': 12,27,462 cs [100.00%] 2,41,957 migrations [100.00%] 1,68,01,713 faults [100.00%] 7,99,35,29,041 cache-misses 98,808 migrate:mm_migrate_pages [100.00%] 1407.690148814 seconds time elapsed numa02 Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa02': 63,065 cs [100.00%] 14,364 migrations [100.00%] 2,08,118 faults [100.00%] 25,32,59,404 cache-misses 12 migrate:mm_migrate_pages [100.00%] 63.840827219 seconds time elapsed (3.14-rc6 with fix) ------------------- numa01 Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa01': 9,68,911 cs [100.00%] 1,01,414 migrations [100.00%] 88,38,697 faults [100.00%] 4,42,92,51,042 cache-misses 4,25,060 migrate:mm_migrate_pages [100.00%] 685.965331189 seconds time elapsed numa02 Performance counter stats for '/usr/bin/time -f %e %S %U %c %w -o start_bench.out -a ./numa02': 17,543 cs [100.00%] 2,962 migrations [100.00%] 1,17,843 faults [100.00%] 11,80,61,644 cache-misses 12,358 migrate:mm_migrate_pages [100.00%] 20.380132343 seconds time elapsed Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Liu Ping Fan <pingfank@linux.vnet.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07madvise: correct the comment of MADV_DODUMP flagZhang Yanfei
s/MADV_NODUMP/MADV_DONTDUMP/ Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm/readahead.c: inline ra_submitFabian Frederick
Commit f9acc8c7b35a ("readahead: sanify file_ra_state names") left ra_submit with a single function call. Move ra_submit to internal.h and inline it to save some stack. Thanks to Andrew Morton for commenting different versions. Signed-off-by: Fabian Frederick <fabf@skynet.be> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: remove unused arg of set_page_dirty_balance()Miklos Szeredi
There's only one caller of set_page_dirty_balance() and that will call it with page_mkwrite == 0. The page_mkwrite argument was unused since commit b827e496c893 "mm: close page_mkwrite races". Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07memcg: rename high level charging functionsMichal Hocko
mem_cgroup_newpage_charge is used only for charging anonymous memory so it is better to rename it to mem_cgroup_charge_anon. mem_cgroup_cache_charge is used for file backed memory so rename it to mem_cgroup_charge_file. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07memcg: get_mem_cgroup_from_mm()Johannes Weiner
Instead of returning NULL from try_get_mem_cgroup_from_mm() when the mm owner is exiting, just return root_mem_cgroup. This makes sense for all callsites and gets rid of some of them having to fallback manually. [fengguang.wu@intel.com: fix warnings] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: use 'const char *' insted of 'char *' for reason in dump_page()Kirill A. Shutemov
I tried to use 'dump_page(page, __func__)' for debugging, but it triggers warning: warning: passing argument 2 of `dump_page' discards `const' qualifier from pointer target type [enabled by default] Let's convert 'reason' to 'const char *' in dump_page() and friends: we shouldn't modify it anyway. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07res_counter: remove interface for locked charging and unchargingDavid Rientjes
The res_counter_{charge,uncharge}_locked() variants are not used in the kernel outside of the resource counter code itself, so remove the interface. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm, mempolicy: remove per-process flagDavid Rientjes
PF_MEMPOLICY is an unnecessary optimization for CONFIG_SLAB users. There's no significant performance degradation to checking current->mempolicy rather than current->flags & PF_MEMPOLICY in the allocation path, especially since this is considered unlikely(). Running TCP_RR with netperf-2.4.5 through localhost on 16 cpu machine with 64GB of memory and without a mempolicy: threads before after 16 1249409 1244487 32 1281786 1246783 48 1239175 1239138 64 1244642 1241841 80 1244346 1248918 96 1266436 1254316 112 1307398 1312135 128 1327607 1326502 Per-process flags are a scarce resource so we should free them up whenever possible and make them available. We'll be using it shortly for memcg oom reserves. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm, mempolicy: rename slab_node for clarityDavid Rientjes
slab_node() is actually a mempolicy function, so rename it to mempolicy_slab_node() to make it clearer that it used for processes with mempolicies. At the same time, cleanup its code by saving numa_mem_id() in a local variable (since we require a node with memory, not just any node) and remove an obsolete comment that assumes the mempolicy is actually passed into the function. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Tim Hockin <thockin@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: per-thread vma cachingDavidlohr Bueso
This patch is a continuation of efforts trying to optimize find_vma(), avoiding potentially expensive rbtree walks to locate a vma upon faults. The original approach (https://lkml.org/lkml/2013/11/1/410), where the largest vma was also cached, ended up being too specific and random, thus further comparison with other approaches were needed. There are two things to consider when dealing with this, the cache hit rate and the latency of find_vma(). Improving the hit-rate does not necessarily translate in finding the vma any faster, as the overhead of any fancy caching schemes can be too high to consider. We currently cache the last used vma for the whole address space, which provides a nice optimization, reducing the total cycles in find_vma() by up to 250%, for workloads with good locality. On the other hand, this simple scheme is pretty much useless for workloads with poor locality. Analyzing ebizzy runs shows that, no matter how many threads are running, the mmap_cache hit rate is less than 2%, and in many situations below 1%. The proposed approach is to replace this scheme with a small per-thread cache, maximizing hit rates at a very low maintenance cost. Invalidations are performed by simply bumping up a 32-bit sequence number. The only expensive operation is in the rare case of a seq number overflow, where all caches that share the same address space are flushed. Upon a miss, the proposed replacement policy is based on the page number that contains the virtual address in question. Concretely, the following results are seen on an 80 core, 8 socket x86-64 box: 1) System bootup: Most programs are single threaded, so the per-thread scheme does improve ~50% hit rate by just adding a few more slots to the cache. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 50.61% | 19.90 | | patched | 73.45% | 13.58 | +----------------+----------+------------------+ 2) Kernel build: This one is already pretty good with the current approach as we're dealing with good locality. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 75.28% | 11.03 | | patched | 88.09% | 9.31 | +----------------+----------+------------------+ 3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 70.66% | 17.14 | | patched | 91.15% | 12.57 | +----------------+----------+------------------+ 4) Ebizzy: There's a fair amount of variation from run to run, but this approach always shows nearly perfect hit rates, while baseline is just about non-existent. The amounts of cycles can fluctuate between anywhere from ~60 to ~116 for the baseline scheme, but this approach reduces it considerably. For instance, with 80 threads: +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 1.06% | 91.54 | | patched | 99.97% | 14.18 | +----------------+----------+------------------+ [akpm@linux-foundation.org: fix nommu build, per Davidlohr] [akpm@linux-foundation.org: document vmacache_valid() logic] [akpm@linux-foundation.org: attempt to untangle header files] [akpm@linux-foundation.org: add vmacache_find() BUG_ON] [hughd@google.com: add vmacache_valid_mm() (from Oleg)] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: adjust and enhance comments] Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: implement ->map_pages for page cacheKirill A. Shutemov
filemap_map_pages() is generic implementation of ->map_pages() for filesystems who uses page cache. It should be safe to use filemap_map_pages() for ->map_pages() if filesystem use filemap_fault() for ->fault(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Cc: Ning Qu <quning@gmail.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: introduce vm_ops->map_pages()Kirill A. Shutemov
Here's new version of faultaround patchset. It took a while to tune it and collect performance data. First patch adds new callback ->map_pages to vm_operations_struct. ->map_pages() is called when VM asks to map easy accessible pages. Filesystem should find and map pages associated with offsets from "pgoff" till "max_pgoff". ->map_pages() is called with page table locked and must not block. If it's not possible to reach a page without blocking, filesystem should skip it. Filesystem should use do_set_pte() to setup page table entry. Pointer to entry associated with offset "pgoff" is passed in "pte" field in vm_fault structure. Pointers to entries for other offsets should be calculated relative to "pte". Currently VM use ->map_pages only on read page fault path. We try to map FAULT_AROUND_PAGES a time. FAULT_AROUND_PAGES is 16 for now. Performance data for different FAULT_AROUND_ORDER is below. TODO: - implement ->map_pages() for shmem/tmpfs; - modify get_user_pages() to be able to use ->map_pages() and implement mmap(MAP_POPULATE|MAP_NONBLOCK) on top. ========================================================================= Tested on 4-socket machine (120 threads) with 128GiB of RAM. Few real-world workloads. The sweet spot for FAULT_AROUND_ORDER here is somewhere between 3 and 5. Let's say 4 :) Linux build (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 283,301,572 247,151,987 212,215,789 204,772,882 199,568,944 194,703,779 193,381,485 time, seconds 151.227629483 153.920996480 151.356125472 150.863792049 150.879207877 151.150764954 151.450962358 Linux rebuild (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 5,396,854 4,148,444 2,855,286 2,577,282 2,361,957 2,169,573 2,112,643 time, seconds 27.404543757 27.559725591 27.030057426 26.855045126 26.678618635 26.974523490 26.761320095 Git test suite (make -j60 test) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 129,591,823 99,200,751 66,106,718 57,606,410 51,510,808 45,776,813 44,085,515 time, seconds 66.087215026 64.784546905 64.401156567 65.282708668 66.034016829 66.793780811 67.237810413 Two synthetic tests: access every word in file in sequential/random order. It doesn't improve much after FAULT_AROUND_ORDER == 4. Sequential access 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 4,195,437 2,098,275 525,068 262,251 131,170 32,856 8,282 time, seconds 7.250461742 6.461711074 5.493859139 5.488488147 5.707213983 5.898510832 5.109232856 8 threads minor-faults 33,557,540 16,892,728 4,515,848 2,366,999 1,423,382 442,732 142,339 time, seconds 16.649304881 9.312555263 6.612490639 6.394316732 6.669827501 6.75078944 6.371900528 32 threads minor-faults 134,228,222 67,526,810 17,725,386 9,716,537 4,763,731 1,668,921 537,200 time, seconds 49.164430543 29.712060103 12.938649729 10.175151004 11.840094583 9.594081325 9.928461797 60 threads minor-faults 251,687,988 126,146,952 32,919,406 18,208,804 10,458,947 2,733,907 928,217 time, seconds 86.260656897 49.626551828 22.335007632 17.608243696 16.523119035 16.339489186 16.326390902 120 threads minor-faults 503,352,863 252,939,677 67,039,168 35,191,827 19,170,091 4,688,357 1,471,862 time, seconds 124.589206333 79.757867787 39.508707872 32.167281632 29.972989292 28.729834575 28.042251622 Random access 1GiB file 1 thread minor-faults 262,636 132,743 34,369 17,299 8,527 3,451 1,222 time, seconds 15.351890914 16.613802482 16.569227308 15.179220992 16.557356122 16.578247824 15.365266994 8 threads minor-faults 2,098,948 1,061,871 273,690 154,501 87,110 25,663 7,384 time, seconds 15.040026343 15.096933500 14.474757288 14.289129964 14.411537468 14.296316837 14.395635804 32 threads minor-faults 8,390,734 4,231,023 1,054,432 528,847 269,242 97,746 26,881 time, seconds 20.430433109 21.585235358 22.115062928 14.872878951 14.880856305 14.883370649 14.821261690 60 threads minor-faults 15,733,258 7,892,809 1,973,393 988,266 594,789 164,994 51,691 time, seconds 26.577302548 25.692397770 18.728863715 20.153026398 21.619101933 17.745086260 17.613215273 120 threads minor-faults 31,471,111 15,816,616 3,959,209 1,978,685 1,008,299 264,635 96,010 time, seconds 41.835322703 40.459786095 36.085306105 35.313894834 35.814445675 36.552633793 34.289210594 Touch only one page in page table in 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 8,372 8,324 8,270 8,260 8,249 8,239 8,237 time, seconds 0.039892712 0.045369149 0.051846126 0.063681685 0.079095975 0.17652406 0.541213386 8 threads minor-faults 65,731 65,681 65,628 65,620 65,608 65,599 65,596 time, seconds 0.124159196 0.488600638 0.156854426 0.191901957 0.242631486 0.543569456 1.677303984 32 threads minor-faults 262,388 262,341 262,285 262,276 262,266 262,257 263,183 time, seconds 0.452421421 0.488600638 0.565020946 0.648229739 0.789850823 1.651584361 5.000361559 60 threads minor-faults 491,822 491,792 491,723 491,711 491,701 491,691 491,825 time, seconds 0.763288616 0.869620515 0.980727360 1.161732354 1.466915814 3.04041448 9.308612938 120 threads minor-faults 983,466 983,655 983,366 983,372 983,363 984,083 984,164 time, seconds 1.595846553 1.667902182 2.008959376 2.425380942 2.941368804 5.977807890 18.401846125 This patch (of 2): Introduce new vm_ops callback ->map_pages() and uses it for mapping easy accessible pages around fault address. On read page fault, if filesystem provides ->map_pages(), we try to map up to FAULT_AROUND_PAGES pages around page fault address in hope to reduce number of minor page faults. We call ->map_pages first and use ->fault() as fallback if page by the offset is not ready to be mapped (cold page cache or something). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Cc: Ning Qu <quning@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLEAlex Thorlton
Add VM_INIT_DEF_MASK, to allow us to set the default flags for VMs. It also adds a prctl control which allows us to set the THP disable bit in mm->def_flags so that VMs will pick up the setting as they are created. Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
2014-04-07sched: remove sleep_on() and friendsArnd Bergmann
This is the final piece in the puzzle, as all patches to remove the last users of \(interruptible_\|\)sleep_on\(_timeout\|\) have made it into the 3.15 merge window. The work was long overdue, and this interface in particular should not have survived the BKL removal that was done a couple of years ago. Citing Jon Corbet from http://lwn.net/2001/0201/kernel.php3": "[...] it was suggested that the janitors look for and fix all code that calls sleep_on() [...] since (1) almost all such code is incorrect, and (2) Linus has agreed that those functions should be removed in the 2.5 development series". We haven't quite made it for 2.5, but maybe we can merge this for 3.15. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client Pull Ceph updates from Sage Weil: "The biggest chunk is a series of patches from Ilya that add support for new Ceph osd and crush map features, including some new tunables, primary affinity, and the new encoding that is needed for erasure coding support. This brings things into parity with the server side and the looming firefly release. There is also support for allocation hints in RBD that help limit fragmentation on the server side. There is also a series of patches from Zheng fixing NFS reexport, directory fragmentation support, flock vs fnctl behavior, and some issues with clustered MDS. Finally, there are some miscellaneous fixes from Yunchuan Wen for fscache, Fabian Frederick for ACLs, and from me for fsync(dirfd) behavior" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (79 commits) ceph: skip invalid dentry during dcache readdir libceph: dump pool {read,write}_tier to debugfs libceph: output primary affinity values on osdmap updates ceph: flush cap release queue when trimming session caps ceph: don't grabs open file reference for aborted request ceph: drop extra open file reference in ceph_atomic_open() ceph: preallocate buffer for readdir reply libceph: enable PRIMARY_AFFINITY feature bit libceph: redo ceph_calc_pg_primary() in terms of ceph_calc_pg_acting() libceph: add support for osd primary affinity libceph: add support for primary_temp mappings libceph: return primary from ceph_calc_pg_acting() libceph: switch ceph_calc_pg_acting() to new helpers libceph: introduce apply_temps() helper libceph: introduce pg_to_raw_osds() and raw_to_up_osds() helpers libceph: ceph_can_shift_osds(pool) and pool type defines libceph: ceph_osd_{exists,is_up,is_down}(osd) definitions libceph: enable OSDMAP_ENC feature bit libceph: primary_affinity decode bits libceph: primary_affinity infrastructure ...
2014-04-07NTB: Code Style Clean-upJon Mason
Some white space and 80 char overruns corrected. Signed-off-by: Jon Mason <jon.mason@intel.com>
2014-04-07NTB: client event cleanupJon Mason
Provide a better event interface between the client and transport Signed-off-by: Jon Mason <jon.mason@intel.com>
2014-04-07Merge tag 'for-f2fs-3.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs updates from Jaegeuk Kim: "This patch-set includes the following major enhancement patches. - introduce large directory support - introduce f2fs_issue_flush to merge redundant flush commands - merge write IOs as much as possible aligned to the segment - add sysfs entries to tune the f2fs configuration - use radix_tree for the free_nid_list to reduce in-memory operations - remove costly bit operations in f2fs_find_entry - enhance the readahead flow for CP/NAT/SIT/SSA blocks The other bug fixes are as follows: - recover xattr node blocks correctly after sudden-power-cut - fix to calculate the maximum number of node ids - enhance to handle many error cases And, there are a bunch of cleanups" * tag 'for-f2fs-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (62 commits) f2fs: fix wrong statistics of inline data f2fs: check the acl's validity before setting f2fs: introduce f2fs_issue_flush to avoid redundant flush issue f2fs: fix to cover io->bio with io_rwsem f2fs: fix error path when fail to read inline data f2fs: use list_for_each_entry{_safe} for simplyfying code f2fs: avoid free slab cache under spinlock f2fs: avoid unneeded lookup when xattr name length is too long f2fs: avoid unnecessary bio submit when wait page writeback f2fs: return -EIO when node id is not matched f2fs: avoid RECLAIM_FS-ON-W warning f2fs: skip unnecessary node writes during fsync f2fs: introduce fi->i_sem to protect fi's info f2fs: change reclaim rate in percentage f2fs: add missing documentation for dir_level f2fs: remove unnecessary threshold f2fs: throttle the memory footprint with a sysfs entry f2fs: avoid to drop nat entries due to the negative nr_shrink f2fs: call f2fs_wait_on_page_writeback instead of native function f2fs: introduce nr_pages_to_write for segment alignment ...
2014-04-07Merge tag 'fbdev-omap-3.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux Pull OMAP fbdev changes from Tomi Valkeinen: "This is based on the already pulled fbdev-main changes, and this also merges .dts branch from Tony Lindgren (which has also been pulled), so that I was able to add the display related .dts changes. This contains OMAP related fbdev changes for 3.15. The bulk of the patches are for adding Device Tree support for OMAP Display Subsystem: - SoCs: OMAP2/3/4 - Boards: OMAP4 Panda, OMAP4 SDP, OMAP3 Beagle, OMAP3 Beagle-xM, OMAP3 IGEP0020, OMAP3 N900 - Devices: TFP410 Encoder, tpd12s015 HDMI companion chip, Sony acx565akm panel, MIPI DSI Command mode panel and HDMI, DVI and Analog TV connectors" * tag 'fbdev-omap-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux: (45 commits) OMAPDSS: HDMI: fix interlace output OMAPDSS: add missing __init for dss_init_ports ARM: OMAP2+: remove pdata quirks for displays OMAPDSS: remove DT hacks for regulators Doc/DT: Add DT binding documentation for tpd12s015 encoder Doc/DT: Add DT binding documentation for TFP410 encoder Doc/DT: Add DT binding documentation for Sony acx565akm panel Doc/DT: Add DT binding documentation for MIPI DSI CM Panel Doc/DT: Add DT binding documentation for HDMI Connector Doc/DT: Add DT binding documentation for DVI Connector Doc/DT: Add DT binding documentation for Analog TV Connector ARM: omap3-n900.dts: add display information ARM: omap3-igep0020.dts: add display information ARM: omap3-beagle-xm.dts: add display information ARM: omap3-beagle.dts: add display information ARM: omap4-sdp.dts: add display information Doc/DT: Add DT binding documentation for OMAP DSS OMAPDSS: acx565akm: Add DT support OMAPDSS: connector-analog-tv: Add DT support OMAPDSS: hdmi-connector: Add DT support ...
2014-04-07Merge tag 'mfd-for-linus-3.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd Pull MFD updates from Lee Jones: "Changes to existing drivers: - Use of managed resources - omap, twl4030, ti_am335x_tscadc - Advanced error handling - omap - Rework clk management - omap - Device Tree (re-)work - tc3589x, pm8921, da9055, sec - IRC management overhaul and !BROKEN - pm8921 - Convert to regmap - ssbi, pm8921 - Use simple power-management ops - ucb1x00 - Include file clean-up - adp5520, cs5535, janz, lpc_ich, - lpc_sch, max14577, mcp-sa11x0, pcf50633-adc, rc5t583, rdc321x-southbridge, retu, smsc-ece1099, ti-ssp, ti_am335x_tscadc, tps65912, vexpress-config, wm8350, ywm8350 - Various bug fixes across the subsystem - NULL/invalid pointer dereference prevention - Resource leak mitigation, - Variable used initialised - Staticise various containers - Enforce return value checks New drivers/supported devices: - Add support for s2mps14 and s2mpa01 to sec - Add support for da9063 (v5) to da9063 - Add support for atom-c2000 to gpio-ich - Add support for come-{mbt10,cbt6,chl6} to kempld - Add support for da9053 to da9052 - Add support for itco-wdt (v3) and baytrail to lpc_ich - Add new drivers for tps65218, rtsx_usb, bcm590xx (Re-)moved drivers: - twl4030 ==> drivers/iio - ti-ssp ==> /dev/null" * tag 'mfd-for-linus-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (103 commits) mfd: wm5110: Correct default for HEADPHONE_DETECT_1 mfd: arizona: Correct small errors in the DT binding documentation mfd: arizona: Mark DSP clocking register as volatile mfd: devicetree: bindings: Add pm8xxx RTC description mfd: kempld-core: Fix potential hang-up during boot mfd: sec-core: Fix uninitialized 'regmap_rtc' on S2MPA01 mfd: tps65910: Fix regmap_irq_chip_data leak on mfd_add_devices fail mfd: tps65910: Fix possible invalid pointer dereference on regmap_add_irq_chip fail mfd: sec-core: Fix I2C dummy device resource leak on probe failure mfd: sec-core: Add of_compatible strings for clock MFD cells mfd: Remove obsolete ti-ssp driver Documentation: mfd: s2mps11: Describe S5M8767 and S2MPS14 clocks mfd: bcm590xx: Fix type argument for module device table mfd: lpc_ich: Add support for Intel Bay Trail SoC mfd: lpc_ich: Add support for NM10 GPIO mfd: lpc_ich: Change Avoton to iTCO v3 watchdog: iTCO_wdt: Add support for v3 silicon mfd: lpc_ich: Add support for iTCO v3 mfd: lpc_ich: Remove lpc_ich_cfg struct use mfd: lpc_ich: Only configure watchdog or GPIO when present ...
2014-04-07Merge tag 'for-linus-20140405' of git://git.infradead.org/linux-mtdLinus Torvalds
Pull MTD updates from Brian Norris: - A few SPI NOR ID definitions - Kill the NAND "max pagesize" restriction - Fix some x16 bus-width NAND support - Add NAND JEDEC parameter page support - DT bindings for NAND ECC - GPMI NAND updates (subpage reads) - More OMAP NAND refactoring - New STMicro SPI NOR driver (now in 40 patches!) - A few other random bugfixes * tag 'for-linus-20140405' of git://git.infradead.org/linux-mtd: (120 commits) Fix index regression in nand_read_subpage mtd: diskonchip: mem resource name is not optional mtd: nand: fix mention to CONFIG_MTD_NAND_ECC_BCH mtd: nand: fix GET/SET_FEATURES address on 16-bit devices mtd: omap2: Use devm_ioremap_resource() mtd: denali_dt: Use devm_ioremap_resource() mtd: devices: elm: update DRIVER_NAME as "omap-elm" mtd: devices: elm: configure parallel channels based on ecc_steps mtd: devices: elm: clean elm_load_syndrome mtd: devices: elm: check for hardware engine's design constraints mtd: st_spi_fsm: Succinctly reorganise .remove() mtd: st_spi_fsm: Allow loop to run at least once before giving up CPU mtd: st_spi_fsm: Correct vendor name spelling issue - missing "M" mtd: st_spi_fsm: Avoid duplicating MTD core code mtd: st_spi_fsm: Remove useless consts from function arguments mtd: st_spi_fsm: Convert ST SPI FSM (NOR) Flash driver to new DT partitions mtd: st_spi_fsm: Move runtime configurable msg sequences into device's struct mtd: st_spi_fsm: Supply the W25Qxxx chip specific configuration call-back mtd: st_spi_fsm: Supply the S25FLxxx chip specific configuration call-back mtd: st_spi_fsm: Supply the MX25xxx chip specific configuration call-back ...
2014-04-07cpufreq: create another field .flags in cpufreq_frequency_tableViresh Kumar
Currently cpufreq frequency table has two fields: frequency and driver_data. driver_data is only for drivers' internal use and cpufreq core shouldn't use it at all. But with the introduction of BOOST frequencies, this assumption was broken and we started using it as a flag instead. There are two problems due to this: - It is against the description of this field, as driver's data is used by the core now. - if drivers fill it with -3 for any frequency, then those frequencies are never considered by cpufreq core as it is exactly same as value of CPUFREQ_BOOST_FREQ, i.e. ~2. The best way to get this fixed is by creating another field flags which will be used for such flags. This patch does that. Along with that various drivers need modifications due to the change of struct cpufreq_frequency_table. Reviewed-by: Gautham R Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-04-07target/sbc: Add sbc_dif_read_strip software emulationNicholas Bellinger
Split up __sbc_dif_verify_read() so that VERIFY READ emulation can perform target-core specific READ_STRIP, seperate from the existing FILEIO/RAMDISK backend emulation code. Also add sbc_dif_read_strip() in order to determine number of sectors using cmd->prot_length, and skip the extra sbc_dif_copy_prot(). Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07target/sbc: Add sbc_dif_generate software emulationNicholas Bellinger
This patch adds WRITE_INSERT emulation within target-core using TYPE1 / TYPE3 PI modes in sbc_dif_generate() code. This is useful in order for existing legacy fabrics that do not support protection offloads to interact with backend devices that currently have T10 PI enabled. v2 changes: - Rename to sbc_dif_generate() (Sagi) Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07target: Pass in transport supported PI at session initializationNicholas Bellinger
In order to support local WRITE_INSERT + READ_STRIP operations for non PI enabled fabrics, the fabric driver needs to be able signal what protection offload operations are supported. This is done at session initialization time so the modes can be signaled by individual se_wwn + se_portal_group endpoints, as well as optionally across different transports on the same endpoint. For iser-target, set TARGET_PROT_ALL if the underlying ib_device has already signaled PI offload support, and allow this to be exposed via a new iscsit_transport->iscsit_get_sup_prot_ops() callback. For loopback, set TARGET_PROT_ALL to signal SCSI initiator mode operation. For all other drivers, set TARGET_PROT_NORMAL to disable fabric level PI. Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07target: Add TFO->abort_task for aborted task resources releaseNicholas Bellinger
Now that TASK_ABORTED status is not generated for all cases by TMR ABORT_TASK + LUN_RESET, a new TFO->abort_task() caller is necessary in order to give fabric drivers a chance to unmap hardware / software resources before the se_cmd descriptor is released via the normal TFO->release_cmd() codepath. This patch adds TFO->aborted_task() in core_tmr_abort_task() in place of the original transport_send_task_abort(), and also updates all fabric drivers to implement this caller. The fabric drivers that include changes to perform cleanup via ->aborted_task() are: - iscsi-target - iser-target - srpt - tcm_qla2xxx The fabric drivers that currently set ->aborted_task() to NOPs are: - loopback - tcm_fc - usb-gadget - sbp-target - vhost-scsi For the latter five, there appears to be no additional cleanup required before invoking TFO->release_cmd() to release the se_cmd descriptor. v2 changes: - Move ->aborted_task() call into transport_cmd_finish_abort (Alex) Cc: Alex Leung <amleung21@yahoo.com> Cc: Mark Rustad <mark.d.rustad@intel.com> Cc: Roland Dreier <roland@kernel.org> Cc: Vu Pham <vu@mellanox.com> Cc: Chris Boot <bootc@bootc.net> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com> Cc: Saurav Kashyap <saurav.kashyap@qlogic.com> Cc: Quinn Tran <quinn.tran@qlogic.com> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07target: Fix Task Aborted Status (TAS) handlingAlex Leung
This patch addresses three of long standing issues wrt to Task Aborted Status (TAS) handling. The first is the incorrect assumption in core_tmr_handle_tas_abort() that TASK_ABORTED status is sent for the task referenced by TMR ABORT_TASK, and sending TASK_ABORTED status for TMR LUN_RESET on the same nexus the LUN_RESET was received. The second is to ensure the lun reference count is dropped within transport_cmd_finish_abort() by calling transport_lun_remove_cmd() before invoking transport_cmd_check_stop_to_fabric(). The last is to fix the delayed TAS handling to allow outstanding WRITEs to complete before sending the TASK_ABORTED status. This includes changing transport_check_aborted_status() to avoid processing when SCF_SEND_DELAYED_TAS has not be set, and updating transport_send_task_abort() to drop the SCF_SENT_DELAYED_TAS check. Signed-off-by: Alex Leung <amleung21@yahoo.com> Cc: Alex Leung <amleung21@yahoo.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07Target/core: Remove prot_handover use for nowSagi Grimberg
This is not going to be supported soon - so drop it. Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2014-04-07Target/dif: Introduce protection-passthough-only modeSagi Grimberg
Some transports (iSCSI/iSER/SRP/FC) support hardware INSERT/STRIP capabilities while other transports like loopback/vhost-scsi need perform this is software. This patch allows fabrics using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC to signal the early LUN scan handling case where PROTECT CDB bits are set, but no fabric buffer has been provided. For transports which use generic new command these buffers have yet to be allocated. Also this way, target may support protection information against legacy initiators (writes are inserted and reads are stripped). (Only set prot_pto for loopback during early special case - nab) Signed-off-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>