From: Michal Hocko <mhocko@suse.com>
To: Sultan Alsawaf <sultan@kerneltoast.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm: vmscan: Replace shrinker_rwsem trylocks with SRCU protection
Date: Wed, 29 Sep 2021 10:06:23 +0200 [thread overview]
Message-ID: <YVQef1zSQ15JNnXP@dhcp22.suse.cz> (raw)
In-Reply-To: <YVH3J+bIGmCLVr0e@sultan-box.localdomain>
On Mon 27-09-21 09:53:59, Sultan Alsawaf wrote:
> On Mon, Sep 27, 2021 at 10:36:36AM +0200, Michal Hocko wrote:
> > Can you be more specific about those scenarios please?
>
> I see frequent tmpfs mounts/unmounts in Android which result in lots of
> superblocks being created and destroyed, and each superblock has its own
> shrinker.
This is an important detail to mention in the changelog. Including some
details about the scale of the problem.
> > I have a vague recollection that this approach has been proposed in the
> > past. Have you checked previous attempts?
>
> I wasn't aware that there were previous attempts. Is this [1] the previous
> attempt you're thinking of? It seems like the thread just died out. Was the main
> gripe that always enabling CONFIG_SRCU increased the kernel's size too much when
> tinyfication was desired?
There were more discussions. I have also found https://lore.kernel.org/lkml/1510609063-3327-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
My memory is quite dim and I do not have time to re-read those
discussions again right now. But if I remember correctly the last one
has died out because a deeper evaluation between the SRCU and rw
semaphores was required.
> Sultan
>
> [1] https://lore.kernel.org/all/153365347929.19074.12509495712735843805.stgit@localhost.localdomain/
--
Michal Hocko
SUSE Labs
prev parent reply other threads:[~2021-09-29 8:06 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-27 7:48 [PATCH] mm: vmscan: Replace shrinker_rwsem trylocks with SRCU protection Sultan Alsawaf
2021-09-27 8:36 ` Michal Hocko
2021-09-27 16:53 ` Sultan Alsawaf
2021-09-29 8:06 ` Michal Hocko [this message]
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