From efb378ef6983c9f7cc7cdb2cc0540a52b05ff916 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Fri, 14 Sep 2018 10:55:26 +0200
Subject: [PATCH 35/49] aio-wait: Increase num_waiters even in home thread
RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <20180914105540.18077-29-kwolf@redhat.com>
Patchwork-id: 82179
O-Subject: [RHV-7.6 qemu-kvm-rhev PATCH 28/42] aio-wait: Increase num_waiters even in home thread
Bugzilla: 1601212
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>
RH-Acked-by: Fam Zheng <famz@redhat.com>
Even if AIO_WAIT_WHILE() is called in the home context of the
AioContext, we still want to allow the condition to change depending on
other threads as long as they kick the AioWait. Specfically block jobs
can be running in an I/O thread and should then be able to kick a drain
in the main loop context.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
include/block/aio-wait.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/block/aio-wait.h b/include/block/aio-wait.h
index c85a62f..600fad1 100644
--- a/include/block/aio-wait.h
+++ b/include/block/aio-wait.h
@@ -76,6 +76,8 @@ typedef struct {
bool waited_ = false; \
AioWait *wait_ = (wait); \
AioContext *ctx_ = (ctx); \
+ /* Increment wait_->num_waiters before evaluating cond. */ \
+ atomic_inc(&wait_->num_waiters); \
if (ctx_ && in_aio_context_home_thread(ctx_)) { \
while ((cond)) { \
aio_poll(ctx_, true); \
@@ -84,8 +86,6 @@ typedef struct {
} else { \
assert(qemu_get_current_aio_context() == \
qemu_get_aio_context()); \
- /* Increment wait_->num_waiters before evaluating cond. */ \
- atomic_inc(&wait_->num_waiters); \
while ((cond)) { \
if (ctx_) { \
aio_context_release(ctx_); \
@@ -96,8 +96,8 @@ typedef struct {
} \
waited_ = true; \
} \
- atomic_dec(&wait_->num_waiters); \
} \
+ atomic_dec(&wait_->num_waiters); \
waited_; })
/**
--
1.8.3.1