From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org
Subject: [PATCH] cpus-common: stop using mb_set/mb_read
Date: Fri, 28 Apr 2023 12:17:35 +0200 [thread overview]
Message-ID: <20230428101735.130779-1-pbonzini@redhat.com> (raw)
Use a store-release at the end of the work item, and a load-acquire when
waiting for the item to be completed. This is the standard message passing
pattern and is both enough and clearer than mb_read/mb_set.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
cpus-common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/cpus-common.c b/cpus-common.c
index b0047e456f93..a53716deb437 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -157,7 +157,7 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data,
wi.exclusive = false;
queue_work_on_cpu(cpu, &wi);
- while (!qatomic_mb_read(&wi.done)) {
+ while (!qatomic_load_acquire(&wi.done)) {
CPUState *self_cpu = current_cpu;
qemu_cond_wait(&qemu_work_cond, mutex);
@@ -363,7 +363,7 @@ void process_queued_cpu_work(CPUState *cpu)
if (wi->free) {
g_free(wi);
} else {
- qatomic_mb_set(&wi->done, true);
+ qatomic_store_release(&wi->done, true);
}
}
qemu_mutex_unlock(&cpu->work_mutex);
--
2.40.0
next reply other threads:[~2023-04-28 10:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-28 10:17 Paolo Bonzini [this message]
2023-04-28 21:52 ` [PATCH] cpus-common: stop using mb_set/mb_read Richard Henderson
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