From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: stefanha@redhat.com
Subject: [Qemu-devel] [PATCH 16/16] aio: push aio_context_acquire/release down to dispatching
Date: Tue, 9 Feb 2016 12:46:14 +0100 [thread overview]
Message-ID: <1455018374-4706-17-git-send-email-pbonzini@redhat.com> (raw)
In-Reply-To: <1455018374-4706-1-git-send-email-pbonzini@redhat.com>
The AioContext data structures are now protected by list_lock and/or
they are walked with FOREACH_RCU primitives. There is no need anymore
to acquire the AioContext for the entire duration of aio_dispatch.
Instead, just acquire it before and after invoking the callbacks.
The next step is then to push it further down.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
aio-posix.c | 15 ++++++---------
aio-win32.c | 15 +++++++--------
async.c | 2 ++
3 files changed, 15 insertions(+), 17 deletions(-)
diff --git a/aio-posix.c b/aio-posix.c
index cbdc6e4..015d41a 100644
--- a/aio-posix.c
+++ b/aio-posix.c
@@ -334,7 +334,9 @@ bool aio_dispatch(AioContext *ctx)
if (!node->deleted &&
(revents & (G_IO_IN | G_IO_HUP | G_IO_ERR)) &&
node->io_read) {
+ aio_context_acquire(ctx);
node->io_read(node->opaque);
+ aio_context_release(ctx);
/* aio_notify() does not count as progress */
if (node->opaque != &ctx->notifier) {
@@ -344,7 +346,9 @@ bool aio_dispatch(AioContext *ctx)
if (!node->deleted &&
(revents & (G_IO_OUT | G_IO_ERR)) &&
node->io_write) {
+ aio_context_acquire(ctx);
node->io_write(node->opaque);
+ aio_context_release(ctx);
progress = true;
}
@@ -360,7 +364,9 @@ bool aio_dispatch(AioContext *ctx)
qemu_lockcnt_dec(&ctx->list_lock);
/* Run our timers */
+ aio_context_acquire(ctx);
progress |= timerlistgroup_run_timers(&ctx->tlg);
+ aio_context_release(ctx);
return progress;
}
@@ -418,7 +424,6 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
bool progress;
int64_t timeout;
- aio_context_acquire(ctx);
progress = false;
/* aio_notify can avoid the expensive event_notifier_set if
@@ -447,9 +452,6 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
timeout = blocking ? aio_compute_timeout(ctx) : 0;
/* wait until next event */
- if (timeout) {
- aio_context_release(ctx);
- }
if (aio_epoll_check_poll(ctx, pollfds, npfd, timeout)) {
AioHandler epoll_handler;
@@ -464,9 +466,6 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
if (blocking) {
atomic_sub(&ctx->notify_me, 2);
}
- if (timeout) {
- aio_context_acquire(ctx);
- }
aio_notify_accept(ctx);
@@ -485,8 +484,6 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
progress = true;
}
- aio_context_release(ctx);
-
return progress;
}
diff --git a/aio-win32.c b/aio-win32.c
index 862f48c..7e90dfd 100644
--- a/aio-win32.c
+++ b/aio-win32.c
@@ -245,7 +245,9 @@ static bool aio_dispatch_handlers(AioContext *ctx, HANDLE event)
if (!node->deleted &&
(revents || event_notifier_get_handle(node->e) == event) &&
node->io_notify) {
+ aio_context_acquire(ctx);
node->io_notify(node->e);
+ aio_context_release(ctx);
/* aio_notify() does not count as progress */
if (node->e != &ctx->notifier) {
@@ -256,11 +258,15 @@ static bool aio_dispatch_handlers(AioContext *ctx, HANDLE event)
if (!node->deleted &&
(node->io_read || node->io_write)) {
if ((revents & G_IO_IN) && node->io_read) {
+ aio_context_acquire(ctx);
node->io_read(node->opaque);
+ aio_context_release(ctx);
progress = true;
}
if ((revents & G_IO_OUT) && node->io_write) {
+ aio_context_acquire(ctx);
node->io_write(node->opaque);
+ aio_context_release(ctx);
progress = true;
}
@@ -305,7 +311,6 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
int count;
int timeout;
- aio_context_acquire(ctx);
progress = false;
/* aio_notify can avoid the expensive event_notifier_set if
@@ -347,17 +352,11 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
timeout = blocking && !have_select_revents
? qemu_timeout_ns_to_ms(aio_compute_timeout(ctx)) : 0;
- if (timeout) {
- aio_context_release(ctx);
- }
ret = WaitForMultipleObjects(count, events, FALSE, timeout);
if (blocking) {
assert(first);
atomic_sub(&ctx->notify_me, 2);
}
- if (timeout) {
- aio_context_acquire(ctx);
- }
if (first) {
aio_notify_accept(ctx);
@@ -380,8 +379,8 @@ bool aio_poll_internal(AioContext *ctx, bool blocking)
progress |= aio_dispatch_handlers(ctx, event);
} while (count > 0);
+ aio_context_acquire(ctx);
progress |= timerlistgroup_run_timers(&ctx->tlg);
-
aio_context_release(ctx);
return progress;
}
diff --git a/async.c b/async.c
index 43a765b..03a8e69 100644
--- a/async.c
+++ b/async.c
@@ -88,7 +88,9 @@ int aio_bh_poll(AioContext *ctx)
ret = 1;
}
bh->idle = 0;
+ aio_context_acquire(ctx);
aio_bh_call(bh);
+ aio_context_release(ctx);
}
}
--
2.5.0
next prev parent reply other threads:[~2016-02-09 11:46 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-09 11:45 [Qemu-devel] [PATCH v3 00/16] aio: first part of aio_context_acquire/release pushdown Paolo Bonzini
2016-02-09 11:45 ` [Qemu-devel] [PATCH 01/16] aio: introduce aio_context_in_iothread Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 02/16] aio: do not really acquire/release the main AIO context Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 03/16] aio: introduce aio_poll_internal Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 04/16] aio: only call aio_poll_internal from iothread Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 05/16] iothread: release AioContext around aio_poll Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 06/16] qemu-thread: introduce QemuRecMutex Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 07/16] aio: convert from RFifoLock to QemuRecMutex Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 08/16] aio: rename bh_lock to list_lock Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 09/16] qemu-thread: introduce QemuLockCnt Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 10/16] aio: make ctx->list_lock a QemuLockCnt, subsuming ctx->walking_bh Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 11/16] qemu-thread: optimize QemuLockCnt with futexes on Linux Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 12/16] aio: tweak walking in dispatch phase Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 13/16] aio-posix: remove walking_handlers, protecting AioHandler list with list_lock Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 14/16] aio-win32: " Paolo Bonzini
2016-02-09 11:46 ` [Qemu-devel] [PATCH 15/16] aio: document locking Paolo Bonzini
2016-02-09 11:46 ` Paolo Bonzini [this message]
2016-02-09 14:01 ` [Qemu-devel] [PATCH v3 00/16] aio: first part of aio_context_acquire/release pushdown Stefan Hajnoczi
-- strict thread matches above, loose matches on Subject: below --
2016-02-08 16:14 [Qemu-devel] [PATCH v2 " Paolo Bonzini
2016-02-08 16:15 ` [Qemu-devel] [PATCH 16/16] aio: push aio_context_acquire/release down to dispatching Paolo Bonzini
2016-01-15 15:12 [Qemu-devel] [PATCH 00/16] aio: first part of aio_context_acquire/release pushdown Paolo Bonzini
2016-01-15 15:12 ` [Qemu-devel] [PATCH 16/16] aio: push aio_context_acquire/release down to dispatching Paolo Bonzini
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