From: Michal Hocko <mhocko@suse.com>
To: Zihuan Zhang <zhangzihuan@kylinos.cn>
Cc: "Rafael J . Wysocki" <rafael@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Oleg Nesterov <oleg@redhat.com>,
David Hildenbrand <david@redhat.com>,
Jonathan Corbet <corbet@lwn.net>, Ingo Molnar <mingo@redhat.com>,
Juri Lelli <juri.lelli@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ben Segall <bsegall@google.com>, Mel Gorman <mgorman@suse.de>,
Valentin Schneider <vschneid@redhat.com>,
len brown <len.brown@intel.com>, pavel machek <pavel@kernel.org>,
Kees Cook <kees@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Lorenzo Stoakes <lorenzo.stoakes@oracle.com>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>, Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Nico Pache <npache@redhat.com>, xu xin <xu.xin16@zte.com.cn>,
wangfushuai <wangfushuai@baidu.com>,
Andrii Nakryiko <andrii@kernel.org>,
Christian Brauner <brauner@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Jeff Layton <jlayton@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>,
Adrian Ratiu <adrian.ratiu@collabora.com>,
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 0/9] freezer: Introduce freeze priority model to address process dependency issues
Date: Fri, 8 Aug 2025 09:00:37 +0200 [thread overview]
Message-ID: <aJWglTo1xpXXEqEM@tiehlicka> (raw)
In-Reply-To: <4c46250f-eb0f-4e12-8951-89431c195b46@kylinos.cn>
On Fri 08-08-25 09:13:30, Zihuan Zhang wrote:
[...]
> However, in practice, we’ve observed cases where tasks appear stuck in
> uninterruptible sleep (D state) during the freeze phase — and thus cannot
> respond to signals or enter the refrigerator. These tasks are technically
> TASK_FREEZABLE, but due to the nature of their sleep state, they don’t
> freeze promptly, and may require multiple retry rounds, or cause the entire
> suspend to fail.
Right, but that is an inherent problem of the freezer implemenatation.
It is not really clear to me how priorities or layers improve on that.
Could you please elaborate on that?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2025-08-08 7:00 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-07 12:14 [RFC PATCH v1 0/9] freezer: Introduce freeze priority model to address process dependency issues Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 1/9] freezer: Introduce freeze_priority field in task_struct Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 2/9] freezer: Introduce API to set per-task freeze priority Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 3/9] freezer: Add per-priority layered freeze logic Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 4/9] freezer: Set default freeze priority for userspace tasks Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 5/9] freezer: set default freeze priority for PF_SUSPEND_TASK processes Zihuan Zhang
2025-08-08 14:39 ` Oleg Nesterov
2025-08-11 9:25 ` Zihuan Zhang
2025-08-11 9:32 ` Oleg Nesterov
2025-08-11 9:42 ` Zihuan Zhang
2025-08-11 9:46 ` Oleg Nesterov
2025-08-11 9:54 ` Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 6/9] freezer: Set default freeze priority for zombie tasks Zihuan Zhang
2025-08-08 14:29 ` Oleg Nesterov
2025-08-11 9:29 ` Zihuan Zhang
2025-08-11 9:42 ` Oleg Nesterov
2025-08-12 8:07 ` Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 7/9] freezer: raise freeze priority of tasks failed to freeze last time Zihuan Zhang
2025-08-08 14:53 ` Oleg Nesterov
2025-08-11 9:31 ` Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 8/9] freezer: Add retry count statistics for freeze pass iterations Zihuan Zhang
2025-08-07 12:14 ` [RFC PATCH v1 9/9] proc: Add /proc/<pid>/freeze_priority interface Zihuan Zhang
2025-08-07 13:25 ` [RFC PATCH v1 0/9] freezer: Introduce freeze priority model to address process dependency issues Michal Hocko
2025-08-08 1:13 ` Zihuan Zhang
2025-08-08 7:00 ` Michal Hocko [this message]
2025-08-08 7:52 ` Zihuan Zhang
2025-08-08 8:58 ` Michal Hocko
2025-08-11 9:13 ` Zihuan Zhang
2025-08-11 10:58 ` Michal Hocko
2025-08-12 5:57 ` Zihuan Zhang
2025-08-12 17:26 ` Darrick J. Wong
2025-08-13 5:48 ` Zihuan Zhang
2025-08-14 16:43 ` Darrick J. Wong
2025-08-15 8:17 ` Zihuan Zhang
2025-08-08 7:57 ` Oleg Nesterov
2025-08-08 8:40 ` Zihuan Zhang
2025-08-14 14:37 ` Peter Zijlstra
2025-08-15 8:27 ` Zihuan Zhang
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