diff options
| author | Jens Axboe <jens.axboe@oracle.com> | 2008-12-09 08:11:22 +0100 |
|---|---|---|
| committer | Jens Axboe <jens.axboe@oracle.com> | 2008-12-29 08:29:50 +0100 |
| commit | abf137dd7712132ee56d5b3143c2ff61a72a5faa (patch) | |
| tree | 8334f03c598343bb93340f081fcde5ba659b440b /include/linux | |
| parent | 392ddc32982a5c661dd90dd49a3cb37f1c68b782 (diff) | |
aio: make the lookup_ioctx() lockless
The mm->ioctx_list is currently protected by a reader-writer lock,
so we always grab that lock on the read side for doing ioctx
lookups. As the workload is extremely reader biased, turn this into
an rcu hlist so we can make lookup_ioctx() lockless. Get rid of
the rwlock and use a spinlock for providing update side exclusion.
There's usually only 1 entry on this list, so it doesn't make sense
to look into fancier data structures.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/aio.h | 5 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 5 |
2 files changed, 7 insertions, 3 deletions
diff --git a/include/linux/aio.h b/include/linux/aio.h index f6b8cf99b59..b16a957030f 100644 --- a/include/linux/aio.h +++ b/include/linux/aio.h @@ -5,6 +5,7 @@ #include <linux/workqueue.h> #include <linux/aio_abi.h> #include <linux/uio.h> +#include <linux/rcupdate.h> #include <asm/atomic.h> @@ -183,7 +184,7 @@ struct kioctx { /* This needs improving */ unsigned long user_id; - struct kioctx *next; + struct hlist_node list; wait_queue_head_t wait; @@ -199,6 +200,8 @@ struct kioctx { struct aio_ring_info ring_info; struct delayed_work wq; + + struct rcu_head rcu_head; }; /* prototypes */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index fe825471d5a..9cfc9b627fd 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -232,8 +232,9 @@ struct mm_struct { struct core_state *core_state; /* coredumping support */ /* aio bits */ - rwlock_t ioctx_list_lock; /* aio lock */ - struct kioctx *ioctx_list; + spinlock_t ioctx_lock; + struct hlist_head ioctx_list; + #ifdef CONFIG_MM_OWNER /* * "owner" points to a task that is regarded as the canonical |