summaryrefslogtreecommitdiff
path: root/arch/ia64/sn/kernel/sn2/sn2_smp.c
AgeCommit message (Collapse)Author
2006-03-21Pull sn2-mmio-writes into release branchTony Luck
Hand-fixed conflicts: include/asm-ia64/machvec_sn2.h Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-03-07[IA64] don't report !sn2 or !summit hardware as an errorBjorn Helgaas
This stuff is all in the generic ia64 kernel, and the new initcall error reporting complains about them. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-02-15[IA64-SGI] sn2 minor fixes and cleanupsJes Sorensen
General SN2 code cleanup: - Do not initialize global variables to zero - Use kzalloc instead of kmalloc+memset - Check kmalloc return values - Do not obfuscate spin lock calls - Remove some unused code - Various formatting cleanups Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2006-01-26[IA64] hooks to wait for mmio writes to drain when migrating processesBrent Casavant
On SN2, MMIO writes which are issued from separate processors are not guaranteed to arrive in any particular order at the IO hardware. When performing such writes from the kernel this is not a problem, as a kernel thread will not migrate to another CPU during execution, and mmiowb() calls can guarantee write ordering when control of the IO resource is allowed to move between threads. However, when MMIO writes can be performed from user space (e.g. DRM) there are no such guarantees and mechanisms, as the process may context-switch at any time, and may migrate to a different CPU as part of the switch. For such programs/hardware to operate correctly, it is required that the MMIO writes from the old CPU be accepted by the IO hardware before subsequent writes from the new CPU can be issued. The following patch implements this behavior on SN2 by waiting for a Shub register to indicate that these writes have been accepted. This is placed in the context switch-in path, and only performs the wait when the newly scheduled task changes CPUs. Signed-off-by: Prarit Bhargava <prarit@sgi.com> Signed-off-by: Brent Casavant <bcasavan@sgi.com>
2006-01-26[IA64-SGI] Update TLB flushing code for SN platformJack Steiner
This patch finishes support for SHUB2 (the new chipset). Most of the changes are performance related. A few changes are workarounds for "interesting" chipset features. Some temporary debugging code has also been deleted. Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-12-16[IA64-SGI] Missed TLB flushJack Steiner
I see why the problem exists only on SN. SN uses a different hardware mechanism to purge TLB entries across nodes. It looks like there is a bug in the SN TLB flushing code. During context switch, kernel threads inherit the mm of the task that was previously running on the cpu. This confuses the code in sn2_global_tlb_purge(). The result is a missed TLB purge for the task that owns the "borrowed" mm. (I hit the problem running heavy stress where kswapd was purging code pages of a user task that woke kswapd. The user task took a SIGILL fault trying to execute code in the page that had been ripped out from underneath it). Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-11-21[IA64] Prevent sn2 ptc code from executing on all ia64 subarchesPrarit Bhargava
Patch to prevent sn2_ptc_init code from attempting to load on non-sn2 systems when sn2_smp.c is built-in to generic kernel. Signed-off-by: Prarit Bhargava <prarit@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-10-27[IA64] - Avoid slow TLB purges on SGI Altix systemsDean Roe
flush_tlb_all() can be a scaling issue on large SGI Altix systems since it uses the global call_lock and always executes on all cpus. When a process enters flush_tlb_range() to purge TLBs for another process, it is possible to avoid flush_tlb_all() and instead allow sn2_global_tlb_purge() to purge TLBs only where necessary. This patch modifies flush_tlb_range() so that this case can be handled by platform TLB purge functions and updates ia64_global_tlb_purge() accordingly. sn2_global_tlb_purge() now calculates the region register value from the mm argument introduced with this patch. Signed-off-by: Dean Roe <roe@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-08-17[IA64-SGI] - New SN hardware support - ptc_fixesJack Steiner
Shub2 provides a much improved mechanism for issuing internode TLB purges. Add code to support the newer mechanism. There is also some debug code (disabled) that is useful for testing. Collect statistics on the number, type & duration of TLB purges. This data will be useful for making future improvements in the algorithms. Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
2005-04-16Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!