From: Oleg Nesterov <oleg@redhat.com>
To: Christian Brauner <brauner@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>, Jann Horn <jannh@google.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
akpm@linux-foundation.org, hca@linux.ibm.com,
linux-s390@vger.kernel.org, david@kernel.org, mhocko@suse.com,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
surenb@google.com, timmurray@google.com
Subject: Re: [PATCH v3] mm: process_mrelease: introduce PROCESS_MRELEASE_REAP_KILL flag
Date: Fri, 15 May 2026 22:15:53 +0200 [thread overview]
Message-ID: <agd--WZpeTq2iKFW@redhat.com> (raw)
In-Reply-To: <20260515-nachdenken-umbenannt-a90006a46e14@brauner>
In fact I don't even understand the motivation...
On 05/15, Christian Brauner wrote:
>
> On Mon, May 11, 2026 at 02:42:26PM -0700, Minchan Kim wrote:
> > leaving the actual address space teardown (exit_mmap) to be deferred until
> > the mm's reference count drops to zero. In the field (e.g., Android),
> > arbitrary reference counts (reading /proc/<pid>/cmdline, or various other
> > remote VM accesses) frequently delay this teardown indefinitely,
Sure, get_task_cmdline() can delay mmput(). But indefinitely ?
Perhaps the changelog could be more clear? I don't see how any remote VM access
can pin mm->mm_users "indefinitely". Even if, say, a lot of threads read
/proc/<pid>/cmdline in an endless loop in parallel...
I must have missed something.
Oleg.
next prev parent reply other threads:[~2026-05-15 20:16 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-11 21:42 [PATCH v3] mm: process_mrelease: introduce PROCESS_MRELEASE_REAP_KILL flag Minchan Kim
2026-05-15 14:41 ` Christian Brauner
2026-05-15 15:49 ` Oleg Nesterov
2026-05-15 20:15 ` Oleg Nesterov [this message]
2026-05-15 22:33 ` Minchan Kim
2026-05-15 23:45 ` Linus Torvalds
2026-05-16 0:00 ` Linus Torvalds
2026-05-15 20:42 ` Suren Baghdasaryan
2026-05-15 20:52 ` Minchan Kim
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