diff options
| author | Kent Overstreet <kmo@daterainc.com> | 2014-01-19 08:26:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-13 13:50:19 -0800 |
| commit | 8cf2461787d8870b637f04c3c1cc9e7b2c3ade7d (patch) | |
| tree | 023b515195f3890c9e52e6061685b8675d5cfb41 /lib | |
| parent | 13f048657763363335d585ec5ffc1212df77bc97 (diff) | |
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask
commit 6f6b5d1ec56acdeab0503d2b823f6f88a0af493e upstream.
This patch changes percpu_ida_alloc() + callers to accept task state
bitmask for prepare_to_wait() for code like target/iscsi that needs
it for interruptible sleep, that is provided in a subsequent patch.
It now expects TASK_UNINTERRUPTIBLE when the caller is able to sleep
waiting for a new tag, or TASK_RUNNING when the caller cannot sleep,
and is forced to return a negative value when no tags are available.
v2 changes:
- Include blk-mq + tcm_fc + vhost/scsi + target/iscsi changes
- Drop signal_pending_state() call
v3 changes:
- Only call prepare_to_wait() + finish_wait() when != TASK_RUNNING
(PeterZ)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/percpu_ida.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c index bab1ba2a4c71..6f6a92d5075b 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -142,22 +142,22 @@ static inline unsigned alloc_local_tag(struct percpu_ida *pool, /** * percpu_ida_alloc - allocate a tag * @pool: pool to allocate from - * @gfp: gfp flags + * @state: task state for prepare_to_wait * * Returns a tag - an integer in the range [0..nr_tags) (passed to * tag_pool_init()), or otherwise -ENOSPC on allocation failure. * * Safe to be called from interrupt context (assuming it isn't passed - * __GFP_WAIT, of course). + * TASK_UNINTERRUPTIBLE, of course). * * @gfp indicates whether or not to wait until a free id is available (it's not * used for internal memory allocations); thus if passed __GFP_WAIT we may sleep * however long it takes until another thread frees an id (same semantics as a * mempool). * - * Will not fail if passed __GFP_WAIT. + * Will not fail if passed TASK_UNINTERRUPTIBLE. */ -int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) +int percpu_ida_alloc(struct percpu_ida *pool, int state) { DEFINE_WAIT(wait); struct percpu_ida_cpu *tags; @@ -184,7 +184,8 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) * * global lock held and irqs disabled, don't need percpu lock */ - prepare_to_wait(&pool->wait, &wait, TASK_UNINTERRUPTIBLE); + if (state != TASK_RUNNING) + prepare_to_wait(&pool->wait, &wait, state); if (!tags->nr_free) alloc_global_tags(pool, tags); @@ -201,7 +202,7 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) spin_unlock(&pool->lock); local_irq_restore(flags); - if (tag >= 0 || !(gfp & __GFP_WAIT)) + if (tag >= 0 || state == TASK_RUNNING) break; schedule(); @@ -209,8 +210,9 @@ int percpu_ida_alloc(struct percpu_ida *pool, gfp_t gfp) local_irq_save(flags); tags = this_cpu_ptr(pool->tag_cpu); } + if (state != TASK_RUNNING) + finish_wait(&pool->wait, &wait); - finish_wait(&pool->wait, &wait); return tag; } EXPORT_SYMBOL_GPL(percpu_ida_alloc); |