[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-block] [PATCH 09/18] aio: push aio_context_acquire/release down to
From: |
Paolo Bonzini |
Subject: |
[Qemu-block] [PATCH 09/18] aio: push aio_context_acquire/release down to dispatching |
Date: |
Thu, 6 Aug 2015 15:36:07 +0200 |
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 <address@hidden>
---
aio-posix.c | 15 ++++++---------
aio-win32.c | 16 ++++++++--------
async.c | 2 ++
3 files changed, 16 insertions(+), 17 deletions(-)
diff --git a/aio-posix.c b/aio-posix.c
index d2b51fc..4944595 100644
--- a/aio-posix.c
+++ b/aio-posix.c
@@ -163,7 +163,9 @@ 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) {
@@ -173,7 +175,9 @@ 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;
}
@@ -189,7 +193,9 @@ 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;
}
@@ -247,7 +253,6 @@ bool aio_poll(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
@@ -274,16 +279,10 @@ bool aio_poll(AioContext *ctx, bool blocking)
timeout = blocking ? aio_compute_timeout(ctx) : 0;
/* wait until next event */
- if (timeout) {
- aio_context_release(ctx);
- }
ret = qemu_poll_ns((GPollFD *)pollfds, npfd, timeout);
if (blocking) {
atomic_sub(&ctx->notify_me, 2);
}
- if (timeout) {
- aio_context_acquire(ctx);
- }
aio_notify_accept(ctx);
@@ -302,7 +301,5 @@ bool aio_poll(AioContext *ctx, bool blocking)
progress = true;
}
- aio_context_release(ctx);
-
return progress;
}
diff --git a/aio-win32.c b/aio-win32.c
index a7994b3..929ed49 100644
--- a/aio-win32.c
+++ b/aio-win32.c
@@ -239,7 +239,9 @@ 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) {
@@ -250,11 +252,15 @@ 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;
}
@@ -299,7 +305,6 @@ bool aio_poll(AioContext *ctx, bool blocking)
int count;
int timeout;
- aio_context_acquire(ctx);
progress = false;
/* aio_notify can avoid the expensive event_notifier_set if
@@ -340,17 +345,11 @@ bool aio_poll(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);
@@ -373,8 +372,9 @@ bool aio_poll(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 69b76dc..198c53d 100644
--- a/async.c
+++ b/async.c
@@ -82,7 +82,9 @@ int aio_bh_poll(AioContext *ctx)
ret = 1;
}
bh->idle = 0;
+ aio_context_acquire(ctx);
bh->cb(bh->opaque);
+ aio_context_release(ctx);
}
}
--
2.4.3
- [Qemu-block] [RFC PATCH 00/18] Fine-grained AioContext critical sections, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 02/18] aio: rename bh_lock to list_lock, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 03/18] qemu-thread: introduce QemuLockCnt, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 04/18] aio: make ctx->list_lock a QemuLockCnt, subsuming ctx->walking_bh, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 06/18] aio-posix: remove walking_handlers, protecting AioHandler list with list_lock, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 09/18] aio: push aio_context_acquire/release down to dispatching,
Paolo Bonzini <=
- [Qemu-block] [PATCH 10/18] async: optimize aio_bh_poll, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 16/18] quorum: split quorum_fifo_aio_cb from quorum_aio_cb, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 05/18] aio: tweak walking in dispatch phase, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 08/18] aio: document locking, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 14/18] block: explicitly acquire aiocontext in timers that need it, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 01/18] iothread: release iothread around aio_poll, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 15/18] quorum: use atomics for rewrite_count, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 07/18] aio-win32: remove walking_handlers, protecting AioHandler list with list_lock, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 18/18] aio: update locking documentation, Paolo Bonzini, 2015/08/06
- [Qemu-block] [PATCH 12/18] block: explicitly acquire aiocontext in callbacks that need it, Paolo Bonzini, 2015/08/06