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[72.132.29.68]) by smtp.gmail.com with ESMTPSA id q10sm168327pgs.44.2021.04.08.12.44.23 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 Apr 2021 12:44:24 -0700 (PDT) Subject: Re: [PATCH] block: Fix sys_ioprio_set(.which=IOPRIO_WHO_PGRP) task iteration To: Peter Zijlstra , Oleg Nesterov Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: From: Jens Axboe Message-ID: Date: Thu, 8 Apr 2021 13:44:23 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/8/21 3:46 AM, Peter Zijlstra wrote: > > do_each_pid_thread() { } while_each_pid_thread() is a double loop and > thus break doesn't work as expected. Also, it should be used under > tasklist_lock because otherwise we can race against change_pid() for > PGID/SID. Applied, thanks. -- Jens Axboe