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Wysocki" , Peter Zijlstra , David Hildenbrand , Michal Hocko , Jonathan Corbet , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , len brown , pavel machek , Kees Cook , Andrew Morton , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Catalin Marinas , Nico Pache , xu xin , wangfushuai , Andrii Nakryiko , Christian Brauner , Thomas Gleixner , Jeff Layton , Al Viro , Adrian Ratiu , linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v1 5/9] freezer: set default freeze priority for PF_SUSPEND_TASK processes Message-ID: <20250811093216.GB11928@redhat.com> References: <20250807121418.139765-1-zhangzihuan@kylinos.cn> <20250807121418.139765-6-zhangzihuan@kylinos.cn> <20250808143943.GB21685@redhat.com> <0754e3e3-9c47-47d5-81d9-4574e5b413bc@kylinos.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0754e3e3-9c47-47d5-81d9-4574e5b413bc@kylinos.cn> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Rspam-User: X-Rspamd-Queue-Id: B45DA1A0003 X-Rspamd-Server: rspam06 X-Stat-Signature: sooqudb85w65nhw5enot5xinc7bfdm48 X-HE-Tag: 1754904834-549713 X-HE-Meta: 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 X7S6gTVN +EAXp4OoII7e0OPaCgZNAcGbtMRcAjiRmCnXVTwmInVwh0Ixe79T74tacxwyLL2qulV3O X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 08/11, Zihuan Zhang wrote: > > 在 2025/8/8 22:39, Oleg Nesterov 写道: > >On 08/07, Zihuan Zhang wrote: > >>--- a/kernel/power/process.c > >>+++ b/kernel/power/process.c > >>@@ -147,6 +147,7 @@ int freeze_processes(void) > >> > >> pm_wakeup_clear(0); > >> pm_freezing = true; > >>+ freeze_set_default_priority(current, FREEZE_PRIORITY_NEVER); > >But why? > > > >Again, freeze_task() will return false anyway, this process is > >PF_SUSPEND_TASK. > > I  think there is resaon put it here. For example, systemd-sleep is a > user-space process that executes the suspend flow. > >  If we don’t set its freeze priority explicitly, our current code may end up > with this user process being the last one that cannot freeze. How so? sorry I don't follow. Oleg.