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| author | Peter Maydell <peter.maydell@linaro.org> | 2021-07-21 14:13:32 +0100 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2021-07-21 14:13:32 +0100 |
| commit | 29c7daa00722e84a54f16cd0df46d289146dcda1 (patch) | |
| tree | a83678a510ddec992140935cbc3e5d66f23cc34f /block/linux-aio.c | |
| parent | 033bd16b8afbaafdcef37356705016d9c3c475fa (diff) | |
| parent | d7ddd0a1618a75b31dc308bb37365ce1da972154 (diff) | |
Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/block-pull-request' into staging
Pull request
Stefano's performance regression fix for commit 2558cb8dd4 ("linux-aio:
increasing MAX_EVENTS to a larger hardcoded value").
# gpg: Signature made Wed 21 Jul 2021 14:12:47 BST
# gpg: using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8
* remotes/stefanha-gitlab/tags/block-pull-request:
linux-aio: limit the batch size using `aio-max-batch` parameter
iothread: add aio-max-batch parameter
iothread: generalize iothread_set_param/iothread_get_param
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'block/linux-aio.c')
| -rw-r--r-- | block/linux-aio.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/block/linux-aio.c b/block/linux-aio.c index 3c0527c2bf..0dab507b71 100644 --- a/block/linux-aio.c +++ b/block/linux-aio.c @@ -28,6 +28,9 @@ */ #define MAX_EVENTS 1024 +/* Maximum number of requests in a batch. (default value) */ +#define DEFAULT_MAX_BATCH 32 + struct qemu_laiocb { Coroutine *co; LinuxAioState *ctx; @@ -351,6 +354,10 @@ static int laio_do_submit(int fd, struct qemu_laiocb *laiocb, off_t offset, LinuxAioState *s = laiocb->ctx; struct iocb *iocbs = &laiocb->iocb; QEMUIOVector *qiov = laiocb->qiov; + int64_t max_batch = s->aio_context->aio_max_batch ?: DEFAULT_MAX_BATCH; + + /* limit the batch with the number of available events */ + max_batch = MIN_NON_ZERO(MAX_EVENTS - s->io_q.in_flight, max_batch); switch (type) { case QEMU_AIO_WRITE: @@ -371,7 +378,7 @@ static int laio_do_submit(int fd, struct qemu_laiocb *laiocb, off_t offset, s->io_q.in_queue++; if (!s->io_q.blocked && (!s->io_q.plugged || - s->io_q.in_flight + s->io_q.in_queue >= MAX_EVENTS)) { + s->io_q.in_queue >= max_batch)) { ioq_submit(s); } |