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authorPaolo Bonzini <pbonzini@redhat.com>2016-07-04 18:33:20 +0200
committerStefan Hajnoczi <stefanha@redhat.com>2016-07-18 15:09:31 +0100
commit0187f5c9cb172771ba85c66e3bf61f8cde6d6561 (patch)
tree18529868935e436847aa696c35792c116d24af0e /async.c
parent4e90ccc28e53eb92ecbd0cdb67da454d783ea828 (diff)
downloadqemu-arm-0187f5c9cb172771ba85c66e3bf61f8cde6d6561.tar.gz
linux-aio: share one LinuxAioState within an AioContext
This has better performance because it executes fewer system calls and does not use a bottom half per disk. Originally proposed by Ming Lei. [Changed #include "raw-aio.h" to "block/raw-aio.h" in win32-aio.c to fix build error as reported by Peter Maydell <peter.maydell@linaro.org>. --Stefan] Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Message-id: 1467650000-51385-1-git-send-email-pbonzini@redhat.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> squash! linux-aio: share one LinuxAioState within an AioContext
Diffstat (limited to 'async.c')
-rw-r--r--async.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/async.c b/async.c
index b4bf205a0c..6caa98cd92 100644
--- a/async.c
+++ b/async.c
@@ -29,6 +29,7 @@
#include "block/thread-pool.h"
#include "qemu/main-loop.h"
#include "qemu/atomic.h"
+#include "block/raw-aio.h"
/***********************************************************/
/* bottom halves (can be seen as timers which expire ASAP) */
@@ -242,6 +243,14 @@ aio_ctx_finalize(GSource *source)
qemu_bh_delete(ctx->notify_dummy_bh);
thread_pool_free(ctx->thread_pool);
+#ifdef CONFIG_LINUX_AIO
+ if (ctx->linux_aio) {
+ laio_detach_aio_context(ctx->linux_aio, ctx);
+ laio_cleanup(ctx->linux_aio);
+ ctx->linux_aio = NULL;
+ }
+#endif
+
qemu_mutex_lock(&ctx->bh_lock);
while (ctx->first_bh) {
QEMUBH *next = ctx->first_bh->next;
@@ -282,6 +291,17 @@ ThreadPool *aio_get_thread_pool(AioContext *ctx)
return ctx->thread_pool;
}
+#ifdef CONFIG_LINUX_AIO
+LinuxAioState *aio_get_linux_aio(AioContext *ctx)
+{
+ if (!ctx->linux_aio) {
+ ctx->linux_aio = laio_init();
+ laio_attach_aio_context(ctx->linux_aio, ctx);
+ }
+ return ctx->linux_aio;
+}
+#endif
+
void aio_notify(AioContext *ctx)
{
/* Write e.g. bh->scheduled before reading ctx->notify_me. Pairs
@@ -345,6 +365,9 @@ AioContext *aio_context_new(Error **errp)
false,
(EventNotifierHandler *)
event_notifier_dummy_cb);
+#ifdef CONFIG_LINUX_AIO
+ ctx->linux_aio = NULL;
+#endif
ctx->thread_pool = NULL;
qemu_mutex_init(&ctx->bh_lock);
rfifolock_init(&ctx->lock, aio_rfifolock_cb, ctx);