qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
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



             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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230428101735.130779-1-pbonzini@redhat.com \
    --to=pbonzini@redhat.com \
    --cc=qemu-devel@nongnu.org \
    --cc=richard.henderson@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).