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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-16 21:49:16 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-16 21:49:16 -0400
commitd82312c80860b8b83cd4473ac6eafd244e712061 (patch)
tree028b2e843e9d59d35aeb8924582864f18aa4ca36 /fs/aio.c
parent7d69cff26ceadce8638cb65191285932a3de3d4c (diff)
parent889fa31f00b218a2cef96c32a6b3f57e6d3bf918 (diff)
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Merge branch 'for-4.1/core' of git://git.kernel.dk/linux-block
Pull block layer core bits from Jens Axboe: "This is the core pull request for 4.1. Not a lot of stuff in here for this round, mostly little fixes or optimizations. This pull request contains: - An optimization that speeds up queue runs on blk-mq, especially for the case where there's a large difference between nr_cpu_ids and the actual mapped software queues on a hardware queue. From Chong Yuan. - Honor node local allocations for requests on legacy devices. From David Rientjes. - Cleanup of blk_mq_rq_to_pdu() from me. - exit_aio() fixup from me, greatly speeding up exiting multiple IO contexts off exit_group(). For my particular test case, fio exit took ~6 seconds. A typical case of both exposing RCU grace periods to user space, and serializing exit of them. - Make blk_mq_queue_enter() honor the gfp mask passed in, so we only wait if __GFP_WAIT is set. From Keith Busch. - blk-mq exports and two added helpers from Mike Snitzer, which will be used by the dm-mq code. - Cleanups of blk-mq queue init from Wei Fang and Xiaoguang Wang" * 'for-4.1/core' of git://git.kernel.dk/linux-block: blk-mq: reduce unnecessary software queue looping aio: fix serial draining in exit_aio() blk-mq: cleanup blk_mq_rq_to_pdu() blk-mq: put blk_queue_rq_timeout together in blk_mq_init_queue() block: remove redundant check about 'set->nr_hw_queues' in blk_mq_alloc_tag_set() block: allocate request memory local to request queue blk-mq: don't wait in blk_mq_queue_enter() if __GFP_WAIT isn't set blk-mq: export blk_mq_run_hw_queues blk-mq: add blk_mq_init_allocated_queue and export blk_mq_register_disk
Diffstat (limited to 'fs/aio.c')
-rw-r--r--fs/aio.c45
1 files changed, 30 insertions, 15 deletions
diff --git a/fs/aio.c b/fs/aio.c
index 5785c4b58fea..fa8b16f47f1a 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -77,6 +77,11 @@ struct kioctx_cpu {
unsigned reqs_available;
};
+struct ctx_rq_wait {
+ struct completion comp;
+ atomic_t count;
+};
+
struct kioctx {
struct percpu_ref users;
atomic_t dead;
@@ -115,7 +120,7 @@ struct kioctx {
/*
* signals when all in-flight requests are done
*/
- struct completion *requests_done;
+ struct ctx_rq_wait *rq_wait;
struct {
/*
@@ -572,8 +577,8 @@ static void free_ioctx_reqs(struct percpu_ref *ref)
struct kioctx *ctx = container_of(ref, struct kioctx, reqs);
/* At this point we know that there are no any in-flight requests */
- if (ctx->requests_done)
- complete(ctx->requests_done);
+ if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count))
+ complete(&ctx->rq_wait->comp);
INIT_WORK(&ctx->free_work, free_ioctx);
schedule_work(&ctx->free_work);
@@ -783,7 +788,7 @@ err:
* the rapid destruction of the kioctx.
*/
static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
- struct completion *requests_done)
+ struct ctx_rq_wait *wait)
{
struct kioctx_table *table;
@@ -813,7 +818,7 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
if (ctx->mmap_size)
vm_munmap(ctx->mmap_base, ctx->mmap_size);
- ctx->requests_done = requests_done;
+ ctx->rq_wait = wait;
percpu_ref_kill(&ctx->users);
return 0;
}
@@ -829,18 +834,24 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx,
void exit_aio(struct mm_struct *mm)
{
struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table);
- int i;
+ struct ctx_rq_wait wait;
+ int i, skipped;
if (!table)
return;
+ atomic_set(&wait.count, table->nr);
+ init_completion(&wait.comp);
+
+ skipped = 0;
for (i = 0; i < table->nr; ++i) {
struct kioctx *ctx = table->table[i];
- struct completion requests_done =
- COMPLETION_INITIALIZER_ONSTACK(requests_done);
- if (!ctx)
+ if (!ctx) {
+ skipped++;
continue;
+ }
+
/*
* We don't need to bother with munmap() here - exit_mmap(mm)
* is coming and it'll unmap everything. And we simply can't,
@@ -849,10 +860,12 @@ void exit_aio(struct mm_struct *mm)
* that it needs to unmap the area, just set it to 0.
*/
ctx->mmap_size = 0;
- kill_ioctx(mm, ctx, &requests_done);
+ kill_ioctx(mm, ctx, &wait);
+ }
+ if (!atomic_sub_and_test(skipped, &wait.count)) {
/* Wait until all IO for the context are done. */
- wait_for_completion(&requests_done);
+ wait_for_completion(&wait.comp);
}
RCU_INIT_POINTER(mm->ioctx_table, NULL);
@@ -1331,15 +1344,17 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
{
struct kioctx *ioctx = lookup_ioctx(ctx);
if (likely(NULL != ioctx)) {
- struct completion requests_done =
- COMPLETION_INITIALIZER_ONSTACK(requests_done);
+ struct ctx_rq_wait wait;
int ret;
+ init_completion(&wait.comp);
+ atomic_set(&wait.count, 1);
+
/* Pass requests_done to kill_ioctx() where it can be set
* in a thread-safe way. If we try to set it here then we have
* a race condition if two io_destroy() called simultaneously.
*/
- ret = kill_ioctx(current->mm, ioctx, &requests_done);
+ ret = kill_ioctx(current->mm, ioctx, &wait);
percpu_ref_put(&ioctx->users);
/* Wait until all IO for the context are done. Otherwise kernel
@@ -1347,7 +1362,7 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
* is destroyed.
*/
if (!ret)
- wait_for_completion(&requests_done);
+ wait_for_completion(&wait.comp);
return ret;
}