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([2001:b07:6468:f312:9520:22e6:6416:5c36]) by smtp.gmail.com with ESMTPSA id g185sm7569472wme.10.2019.09.25.09.47.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 25 Sep 2019 09:47:30 -0700 (PDT) Subject: Re: [Qemu-devel] [PATCH v3 0/5] Automatic RCU read unlock To: "Dr. David Alan Gilbert" References: <20190913102538.24167-1-dgilbert@redhat.com> <20190925131324.GG21544@work-vm> <20190925152858.GE2876@work-vm> From: Paolo Bonzini Openpgp: preference=signencrypt Message-ID: Date: Wed, 25 Sep 2019 18:47:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190925152858.GE2876@work-vm> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: quintela@redhat.com, berrange@redhat.com, qemu-devel@nongnu.org, ehabkost@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 25/09/19 17:28, Dr. David Alan Gilbert wrote: > * Paolo Bonzini (pbonzini@redhat.com) wrote: >> On 25/09/19 15:13, Dr. David Alan Gilbert wrote: >>> * Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote: >>>> From: "Dr. David Alan Gilbert" >>>> >>>> This patch uses glib's g_auto mechanism to automatically free >>>> rcu_read_lock's at the end of the block. Given that humans >>>> have a habit of forgetting an error path somewhere it's >>>> best to leave it to the compiler. >>> >>> I've had to unqueue this - clang doesn't like the apparently unused >>> auto variable; we need to find a way to make that happy. >> >> __attribute__((unused))? > > I worry that if I do that, then it'll optimise it out. It cannot, since the function passed to the cleanup attribute can have side effects. Paolo > > Dave > >> Paolo >> >>> Dave >>> >>>> v3 >>>> Add block-head version of macro >>>> Rename >>>> Add docs >>>> Convert more cases using the block-head version >>>> >>>> Dr. David Alan Gilbert (5): >>>> rcu: Add automatically released rcu_read_lock variants >>>> migration: Fix missing rcu_read_unlock >>>> migration: Use automatic rcu_read unlock in ram.c >>>> migration: Use automatic rcu_read unlock in rdma.c >>>> rcu: Use automatic rc_read unlock in core memory/exec code >>>> >>>> docs/devel/rcu.txt | 16 +++ >>>> exec.c | 120 +++++++--------- >>>> include/exec/ram_addr.h | 138 +++++++++---------- >>>> include/qemu/rcu.h | 25 ++++ >>>> memory.c | 15 +- >>>> migration/ram.c | 295 +++++++++++++++++++--------------------- >>>> migration/rdma.c | 57 ++------ >>>> 7 files changed, 310 insertions(+), 356 deletions(-) >>>> >>>> -- >>>> 2.21.0 >>>> >>>> >>> -- >>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >>> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >