diff options
| author | Stefan Hajnoczi | 2020-05-11 20:36:30 +0200 |
|---|---|---|
| committer | Stefan Hajnoczi | 2020-05-18 19:16:00 +0200 |
| commit | ba607ca8bff4d2c2062902f8355657c865ac7c29 (patch) | |
| tree | de002f3ab22e267501feb4b691e51c22662b1753 | |
| parent | aio-posix: don't duplicate fd handler deletion in fdmon_io_uring_destroy() (diff) | |
| download | qemu-ba607ca8bff4d2c2062902f8355657c865ac7c29.tar.gz qemu-ba607ca8bff4d2c2062902f8355657c865ac7c29.tar.xz qemu-ba607ca8bff4d2c2062902f8355657c865ac7c29.zip | |
aio-posix: disable fdmon-io_uring when GSource is used
The glib event loop does not call fdmon_io_uring_wait() so fd handlers
waiting to be submitted build up in the list. There is no benefit is
using io_uring when the glib GSource is being used, so disable it
instead of implementing a more complex fix.
This fixes a memory leak where AioHandlers would build up and increasing
amounts of CPU time were spent iterating them in aio_pending(). The
symptom is that guests become slow when QEMU is built with io_uring
support.
Buglink: https://bugs.launchpad.net/qemu/+bug/1877716
Fixes: 73fd282e7b6dd4e4ea1c3bbb3d302c8db51e4ccf ("aio-posix: add io_uring fd monitoring implementation")
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Message-id: 20200511183630.279750-3-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | include/block/aio.h | 3 | ||||
| -rw-r--r-- | util/aio-posix.c | 12 | ||||
| -rw-r--r-- | util/aio-win32.c | 4 | ||||
| -rw-r--r-- | util/async.c | 1 |
4 files changed, 20 insertions, 0 deletions
diff --git a/include/block/aio.h b/include/block/aio.h index 62ed954344..b2f703fa3f 100644 --- a/include/block/aio.h +++ b/include/block/aio.h @@ -701,6 +701,9 @@ void aio_context_setup(AioContext *ctx); */ void aio_context_destroy(AioContext *ctx); +/* Used internally, do not call outside AioContext code */ +void aio_context_use_g_source(AioContext *ctx); + /** * aio_context_set_poll_params: * @ctx: the aio context diff --git a/util/aio-posix.c b/util/aio-posix.c index 8af334ab19..1b2a3af65b 100644 --- a/util/aio-posix.c +++ b/util/aio-posix.c @@ -682,6 +682,18 @@ void aio_context_destroy(AioContext *ctx) aio_free_deleted_handlers(ctx); } +void aio_context_use_g_source(AioContext *ctx) +{ + /* + * Disable io_uring when the glib main loop is used because it doesn't + * support mixed glib/aio_poll() usage. It relies on aio_poll() being + * called regularly so that changes to the monitored file descriptors are + * submitted, otherwise a list of pending fd handlers builds up. + */ + fdmon_io_uring_destroy(ctx); + aio_free_deleted_handlers(ctx); +} + void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns, int64_t grow, int64_t shrink, Error **errp) { diff --git a/util/aio-win32.c b/util/aio-win32.c index 729d533faf..953c56ab48 100644 --- a/util/aio-win32.c +++ b/util/aio-win32.c @@ -414,6 +414,10 @@ void aio_context_destroy(AioContext *ctx) { } +void aio_context_use_g_source(AioContext *ctx) +{ +} + void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns, int64_t grow, int64_t shrink, Error **errp) { diff --git a/util/async.c b/util/async.c index 3165a28f2f..1319eee3bc 100644 --- a/util/async.c +++ b/util/async.c @@ -362,6 +362,7 @@ static GSourceFuncs aio_source_funcs = { GSource *aio_get_g_source(AioContext *ctx) { + aio_context_use_g_source(ctx); g_source_ref(&ctx->source); return &ctx->source; } |