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Date:   Wed, 23 Mar 2022 09:48:17 -0700
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Waiman Long <longman@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux F2FS Dev Mailing List 
        <linux-f2fs-devel@lists.sourceforge.net>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [GIT PULL] f2fs for 5.18
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On 03/23, Christoph Hellwig wrote:
> On Tue, Mar 22, 2022 at 10:22:50AM -0700, Linus Torvalds wrote:
> > On Mon, Mar 21, 2022 at 1:39 PM Jaegeuk Kim <jaegeuk@kernel.org> wrote:
> > >
> > > In this cycle, f2fs has some performance improvements for Android workloads such
> > > as using read-unfair rwsems [...]
> > 
> > I've pulled this, but that read-unfair rwsem code looks incredibly
> > dodgy. Doing your own locking is always a bad sign, and it ahs
> > traditionally come back to bite us pretty much every time. At least it
> > uses real lock primitives, just in a really odd way.
> 
> FYI, Peter and I both pointed this out when the patches were posted
> and NAKed the patch, but the feedback was ignored.

Christoph, I proposed,

"I've been waiting for a generic solution as suggested here. Until then, I'd like
to keep this in f2fs *only* in order to ship the fix in products. Once there's
a right fix, let me drop or revise this patch again."

https://lore.kernel.org/linux-f2fs-devel/YhZzV11+BlgI1PBd@google.com/