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Tue, 09 May 2023 02:05:06 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ67d4TBaODHtMI5WYC56BF/VYtiKygmHpPL5b1yn38xffVG5L3iOQdBrTFDzm3pmAjLFz+pWQ== X-Received: by 2002:a17:906:ef04:b0:94a:4eba:45d3 with SMTP id f4-20020a170906ef0400b0094a4eba45d3mr10165690ejs.30.1683623106724; Tue, 09 May 2023 02:05:06 -0700 (PDT) Received: from [192.168.10.118] ([2001:b07:6468:f312:9af8:e5f5:7516:fa89]) by smtp.gmail.com with ESMTPSA id ia6-20020a170907a06600b00969c3a9769csm891938ejc.201.2023.05.09.02.05.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 May 2023 02:05:05 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Cc: Richard Henderson Subject: [PULL 05/16] tb-maint: do not use mb_read/mb_set Date: Tue, 9 May 2023 11:04:42 +0200 Message-Id: <20230509090453.37884-6-pbonzini@redhat.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230509090453.37884-1-pbonzini@redhat.com> References: <20230509090453.37884-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org The load side can use a relaxed load, which will surely happen before the work item is run by async_safe_run_on_cpu() or before double-checking under mmap_lock. The store side can use an atomic RMW operation. Reviewed-by: Richard Henderson Signed-off-by: Paolo Bonzini --- accel/tcg/tb-maint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c index cb1f806f00d4..0dd173fbf048 100644 --- a/accel/tcg/tb-maint.c +++ b/accel/tcg/tb-maint.c @@ -746,7 +746,7 @@ static void do_tb_flush(CPUState *cpu, run_on_cpu_data tb_flush_count) tcg_region_reset_all(); /* XXX: flush processor icache at this point if cache flush is expensive */ - qatomic_mb_set(&tb_ctx.tb_flush_count, tb_ctx.tb_flush_count + 1); + qatomic_inc(&tb_ctx.tb_flush_count); done: mmap_unlock(); @@ -758,7 +758,7 @@ done: void tb_flush(CPUState *cpu) { if (tcg_enabled()) { - unsigned tb_flush_count = qatomic_mb_read(&tb_ctx.tb_flush_count); + unsigned tb_flush_count = qatomic_read(&tb_ctx.tb_flush_count); if (cpu_in_exclusive_context(cpu)) { do_tb_flush(cpu, RUN_ON_CPU_HOST_INT(tb_flush_count)); -- 2.40.1