From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kent Overstreet Subject: [PATCH 24/32] aio: Percpu ioctx refcount Date: Wed, 26 Dec 2012 18:00:03 -0800 Message-ID: <1356573611-18590-27-git-send-email-koverstreet@google.com> References: <1356573611-18590-1-git-send-email-koverstreet@google.com> Cc: Kent Overstreet , zab@redhat.com, bcrl@kvack.org, jmoyer@redhat.com, axboe@kernel.dk, viro@zeniv.linux.org.uk, tytso@mit.edu To: linux-kernel@vger.kernel.org, linux-aio@kvack.org, linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1356573611-18590-1-git-send-email-koverstreet@google.com> Sender: owner-linux-aio@kvack.org List-Id: linux-fsdevel.vger.kernel.org This just converts the ioctx refcount to the new generic dynamic percpu refcount code. Signed-off-by: Kent Overstreet --- fs/aio.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index e415b33..b26ad5c 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include @@ -65,8 +66,7 @@ struct kioctx_cpu { }; struct kioctx { - atomic_t users; - atomic_t dead; + struct percpu_ref users; /* This needs improving */ unsigned long user_id; @@ -340,7 +340,7 @@ static void free_ioctx(struct kioctx *ctx) static void put_ioctx(struct kioctx *ctx) { - if (unlikely(atomic_dec_and_test(&ctx->users))) + if (percpu_ref_put(&ctx->users)) free_ioctx(ctx); } @@ -369,8 +369,11 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) ctx->max_reqs = nr_events; - atomic_set(&ctx->users, 2); - atomic_set(&ctx->dead, 0); + percpu_ref_init(&ctx->users); + rcu_read_lock(); + percpu_ref_get(&ctx->users); + rcu_read_unlock(); + spin_lock_init(&ctx->ctx_lock); spin_lock_init(&ctx->completion_lock); mutex_init(&ctx->ring_lock); @@ -442,7 +445,7 @@ static void kill_ioctx_rcu(struct rcu_head *head) */ static void kill_ioctx(struct kioctx *ctx) { - if (!atomic_xchg(&ctx->dead, 1)) { + if (percpu_ref_kill(&ctx->users)) { hlist_del_rcu(&ctx->list); /* Between hlist_del_rcu() and dropping the initial ref */ synchronize_rcu(); @@ -488,12 +491,6 @@ void exit_aio(struct mm_struct *mm) struct hlist_node *p, *n; hlist_for_each_entry_safe(ctx, p, n, &mm->ioctx_list, list) { - if (1 != atomic_read(&ctx->users)) - printk(KERN_DEBUG - "exit_aio:ioctx still alive: %d %d %d\n", - atomic_read(&ctx->users), - atomic_read(&ctx->dead), - atomic_read(&ctx->reqs_available)); /* * We don't need to bother with munmap() here - * exit_mmap(mm) is coming and it'll unmap everything. @@ -504,7 +501,7 @@ void exit_aio(struct mm_struct *mm) */ ctx->mmap_size = 0; - if (!atomic_xchg(&ctx->dead, 1)) { + if (percpu_ref_kill(&ctx->users)) { hlist_del_rcu(&ctx->list); call_rcu(&ctx->rcu_head, kill_ioctx_rcu); } @@ -616,7 +613,7 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id) hlist_for_each_entry_rcu(ctx, n, &mm->ioctx_list, list) if (ctx->user_id == ctx_id){ - atomic_inc(&ctx->users); + percpu_ref_get(&ctx->users); ret = ctx; break; } @@ -830,7 +827,7 @@ static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr, if (ret > 0) *i += ret; - if (unlikely(atomic_read(&ctx->dead))) + if (unlikely(percpu_ref_dead(&ctx->users))) ret = -EINVAL; if (!*i) -- 1.7.12 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to majordomo@kvack.org. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: aart@kvack.org