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[209.85.167.50]) by smtp.gmail.com with ESMTPSA id b25sm4278158lff.42.2019.06.05.10.25.04 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 05 Jun 2019 10:25:04 -0700 (PDT) Received: by mail-lf1-f50.google.com with SMTP id a25so19724150lfg.2 for ; Wed, 05 Jun 2019 10:25:04 -0700 (PDT) X-Received: by 2002:ac2:5601:: with SMTP id v1mr7944437lfd.106.1559755503740; Wed, 05 Jun 2019 10:25:03 -0700 (PDT) MIME-Version: 1.0 References: <20190522032144.10995-1-deepa.kernel@gmail.com> <20190529161157.GA27659@redhat.com> <20190604134117.GA29963@redhat.com> <20190605155801.GA25165@redhat.com> In-Reply-To: <20190605155801.GA25165@redhat.com> From: Linus Torvalds Date: Wed, 5 Jun 2019 10:24:47 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH -mm 0/1] signal: simplify set_user_sigmask/restore_user_sigmask To: Oleg Nesterov Cc: Andrew Morton , Deepa Dinamani , Linux List Kernel Mailing , Arnd Bergmann , Davidlohr Bueso , Jens Axboe , Davidlohr Bueso , e@80x24.org, Jason Baron , linux-fsdevel , linux-aio@kvack.org, omar.kilani@gmail.com, Thomas Gleixner , stable , Al Viro , "Eric W. Biederman" , David Laight Content-Type: multipart/mixed; boundary="000000000000bcd942058a96e0bf" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --000000000000bcd942058a96e0bf Content-Type: text/plain; charset="UTF-8" On Wed, Jun 5, 2019 at 8:58 AM Oleg Nesterov wrote: > > To simplify the review, please see the code with this patch applied. > I am using epoll_pwait() as an example because it looks very simple. I like it. However. I think I'd like it even more if we just said "we don't need restore_saved_sigmask AT ALL". Which would be fairly easy to do with something like the attached... (Yes, this only does x86, which is a problem, but I'm bringing this up as a RFC..) Is it worth another TIF flag? This sure would simplify things, and it really fits the concept too: this really is a do_signal() issue, and fundamentally goes together with TIF_SIGPENDING. 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