linux-kernel - Re: [PATCH v7 1/2] mm/oom_kill: Thaw victim on a per-process basis instead of per-thread

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250904130844.28447-1-zhongjinji@honor.com>
Date: Thu, 4 Sep 2025 21:08:44 +0800
From: zhongjinji <zhongjinji@...or.com>
To: <mhocko@...e.com>
CC: <akpm@...ux-foundation.org>, <feng.han@...or.com>,
	<liam.howlett@...cle.com>, <linux-kernel@...r.kernel.org>,
	<linux-mm@...ck.org>, <liulu.liu@...or.com>, <lorenzo.stoakes@...cle.com>,
	<rientjes@...gle.com>, <shakeel.butt@...ux.dev>, <surenb@...gle.com>,
	<tglx@...utronix.de>, <zhongjinji@...or.com>, <rafael@...nel.org>,
	<pavel@...nel.org>, <linux-pm@...r.kernel.org>
Subject: Re: [PATCH v7 1/2] mm/oom_kill: Thaw victim on a per-process basis instead of per-thread

> > OOM killer is a mechanism that selects and kills processes when the system
> > runs out of memory to reclaim resources and keep the system stable.
> > However, the oom victim cannot terminate on its own when it is frozen,
> > because __thaw_task() only thaws one thread of the victim, while
> > the other threads remain in the frozen state.
> > 
> > This change will thaw the entire victim process when OOM occurs,
> > ensuring that the oom victim can terminate on its own.
> > 
> > Signed-off-by: zhongjinji <zhongjinji@...or.com>
> > ---
> >  mm/oom_kill.c | 19 ++++++++++++++++---
> >  1 file changed, 16 insertions(+), 3 deletions(-)
> > 
> > diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> > index 25923cfec9c6..3caaafc896d4 100644
> > --- a/mm/oom_kill.c
> > +++ b/mm/oom_kill.c
> > @@ -747,6 +747,19 @@ static inline void queue_oom_reaper(struct task_struct *tsk)
> >  }
> >  #endif /* CONFIG_MMU */
> >  
> > +static void thaw_oom_process(struct task_struct *tsk)
> > +{
> > +	struct task_struct *t;
> > +
> > +	/* protects against  __exit_signal() */
> > +	read_lock(&tasklist_lock);
> > +	for_each_thread(tsk, t) {
> > +		set_tsk_thread_flag(t, TIF_MEMDIE);
> > +		__thaw_task(t);
> > +	}
> > +	read_unlock(&tasklist_lock);
> > +}
> > +
> 
> Sorry, I was probably not clear enough. I meant thaw_process should live
> in the freezer proper kernel/freezer.c and oom should be just user.
> Please make sure that freezer maintainers are involved and approve the
> change.

Thank you, I got it, It would indeed be better to have thaw_process in
kernel/freezer.c. Let me CC the freezer maintainers before updating
with the new changes; maybe they will have other suggestions as well.

> 
> -- 
> Michal Hocko
> SUSE Labs