From: Christoph Hellwig <hch@infradead.org>
To: Joanne Koong <joannelkoong@gmail.com>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, jack@suse.cz,
willy@infradead.org, miklos@szeredi.hu, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v1] mm: fix writeback regression for strictlimit BDIs
Date: Wed, 25 Mar 2026 22:50:36 -0700 [thread overview]
Message-ID: <acTJLJdrd_T-cOAu@infradead.org> (raw)
In-Reply-To: <20260326001337.828947-1-joannelkoong@gmail.com>
On Wed, Mar 25, 2026 at 05:13:37PM -0700, Joanne Koong wrote:
> Commit 64dd89ae01f2 ("mm/block/fs: remove laptop_mode") removed this
> unconditional writeback kick from balance_dirty_pages():
>
> if (unlikely(!writeback_in_progress(wb)))
> wb_start_background_writeback(wb);
Yes, that looks like a bug.
> This fixes the issue by kicking off the flusher if wb_dirty exceeds
> wb_bg_thresh for strictlimit BDIs. This restores performance back to its
> original baseline.
What speaks against just reinstating the old-code as-is minus the
misleading latop_mode comment?
next prev parent reply other threads:[~2026-03-26 5:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-26 0:13 [PATCH v1] mm: fix writeback regression for strictlimit BDIs Joanne Koong
2026-03-26 5:50 ` Christoph Hellwig [this message]
2026-03-26 8:48 ` Jan Kara
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