linux-kernel - Re: [PATCH] debugobject: don't wake up kswapd from fill

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Message-ID: <aaff0a39-3dd1-5efb-bb7b-c2c241ac9c06@I-love.SAKURA.ne.jp>
Date:   Sat, 13 May 2023 18:33:16 +0900
From:   Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     syzbot <syzbot+fe0c72f0ccbb93786380@...kaller.appspotmail.com>,
        syzkaller-bugs@...glegroups.com, Ingo Molnar <mingo@...e.hu>,
        linux-kernel@...r.kernel.org, linux-mm <linux-mm@...ck.org>,
        Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH] debugobject: don't wake up kswapd from fill_pool()

On 2023/05/13 17:33, Thomas Gleixner wrote:
> Now I just stared at __alloc_pages_slowpath() and looked at the
> condition for wakeup_all_kswapds(). ALLOC_KSWAPD is set because
> debugobject uses GFP_ATOMIC which contains __GFP_KSWAPD_RECLAIM.
> 
> So debug objects needs to have s/GFP_ATOMIC/__GFP_HIGH/ to prevent that
> wakeup path.

Yes. That is exactly what my patch does.