diff options
| author | Kent Overstreet <kmo@daterainc.com> | 2014-01-19 08:26:37 +0000 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2014-01-23 20:17:18 +0000 |
| commit | 6f6b5d1ec56acdeab0503d2b823f6f88a0af493e (patch) | |
| tree | 7a95dca01cc9ddd652ccbfba4df9d5c30abda549 /lib | |
| parent | 4a4caa29f1abcb14377e05d57c0793d338fb945d (diff) | |
percpu_ida: Make percpu_ida_alloc + callers accept task state bitmask
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>
Cc: <stable@vger.kernel.org> #3.12+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.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 9d054bf91d0f..58b671484ac2 100644 --- a/lib/percpu_ida.c +++ b/lib/percpu_ida.c @@ -132,22 +132,22 @@ static inline unsigned alloc_local_tag(struct percpu_ida_cpu *tags) /** * 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; @@ -174,7 +174,8 @@ 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); @@ -191,7 +192,7 @@ 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(); @@ -199,8 +200,9 @@ 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); |