diff options
| author | Kent Overstreet <koverstreet@google.com> | 2013-02-07 12:32:04 +1100 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2013-02-14 15:26:37 +1100 |
| commit | c8da8d6ec8f577d795eef410386fa00d0b007992 (patch) | |
| tree | 37b2cdf3422308447af54d96b94cb8a50d90823a /include | |
| parent | 61add16ffabf2d71c57e588b64d7507265a2236f (diff) | |
aio: use cancellation list lazily
Cancelling kiocbs requires adding them to a per kioctx linked list, which
is one of the few things we need to take the kioctx lock for in the fast
path. But most kiocbs can't be cancelled - so if we just do this lazily,
we can avoid quite a bit of locking overhead.
While we're at it, instead of using a flag bit switch to using ki_cancel
itself to indicate that a kiocb has been cancelled/completed. This lets
us get rid of ki_flags entirely.
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/aio.h | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/include/linux/aio.h b/include/linux/aio.h index 1e728f0086f8..fc3c467d9e80 100644 --- a/include/linux/aio.h +++ b/include/linux/aio.h @@ -10,17 +10,13 @@ #include <linux/atomic.h> struct kioctx; +struct kiocb; #define KIOCB_SYNC_KEY (~0U) -/* ki_flags bits */ -#define KIF_CANCELLED 2 +#define KIOCB_CANCELLED ((void *) (~0ULL)) -#define kiocbSetCancelled(iocb) set_bit(KIF_CANCELLED, &(iocb)->ki_flags) - -#define kiocbClearCancelled(iocb) clear_bit(KIF_CANCELLED, &(iocb)->ki_flags) - -#define kiocbIsCancelled(iocb) test_bit(KIF_CANCELLED, &(iocb)->ki_flags) +typedef int (kiocb_cancel_fn)(struct kiocb *, struct io_event *); /* is there a better place to document function pointer methods? */ /** @@ -48,13 +44,12 @@ struct kioctx; * calls may result in undefined behaviour. */ struct kiocb { - unsigned long ki_flags; atomic_t ki_users; unsigned ki_key; /* id of this request */ struct file *ki_filp; struct kioctx *ki_ctx; /* may be NULL for sync ops */ - int (*ki_cancel)(struct kiocb *, struct io_event *); + kiocb_cancel_fn *ki_cancel; ssize_t (*ki_retry)(struct kiocb *); void (*ki_dtor)(struct kiocb *); @@ -112,6 +107,7 @@ struct mm_struct; extern void exit_aio(struct mm_struct *mm); extern long do_io_submit(aio_context_t ctx_id, long nr, struct iocb __user *__user *iocbpp, bool compat); +void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel); #else static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; } static inline void aio_put_req(struct kiocb *iocb) { } @@ -121,6 +117,8 @@ static inline void exit_aio(struct mm_struct *mm) { } static inline long do_io_submit(aio_context_t ctx_id, long nr, struct iocb __user * __user *iocbpp, bool compat) { return 0; } +static inline void kiocb_set_cancel_fn(struct kiocb *req, + kiocb_cancel_fn *cancel) { } #endif /* CONFIG_AIO */ static inline struct kiocb *list_kiocb(struct list_head *h) |