Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 9 Aug 2022 18:11:57 +0900
From:   Sergey Senozhatsky <senozhatsky@chromium.org>
To:     Jiri Slaby <jirislaby@kernel.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        minchan@kernel.org, ngupta@vflare.org, Jan Kara <jack@suse.com>,
        Ted Ts'o <tytso@mit.edu>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Ext4 Developers List <linux-ext4@vger.kernel.org>,
        avromanov@sberdevices.ru, ddrokosov@sberdevices.ru,
        Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: Re: ext2/zram issue [was: Linux 5.19]
Message-ID: <YvIk3SdC7wP3uItR@google.com>
References: <CAHk-=wgrz5BBk=rCz7W28Fj_o02s0Xi0OEQ3H1uQgOdFvHgx0w@mail.gmail.com>
 <702b3187-14bf-b733-263b-20272f53105d@kernel.org>
 <c7c69f77-4ea2-3375-33f3-322a3d35def5@kernel.org>
 <8710b302-9415-458d-f8a2-b78cc3a96e49@kernel.org>
 <YvIeLHuEb9XDSp6N@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <YvIeLHuEb9XDSp6N@google.com>
Precedence: bulk

On (22/08/09 17:43), Sergey Senozhatsky wrote:
> On (22/08/09 10:12), Jiri Slaby wrote:
> > > So currently, I blame:
> > > commit e7be8d1dd983156bbdd22c0319b71119a8fbb697
> > > Author: Alexey Romanov <avromanov@sberdevices.ru>
> > > Date:?? Thu May 12 20:23:07 2022 -0700
> > > 
> > >  ??? zram: remove double compression logic
> > > 
> > > 
> > > /me needs to confirm.
> > 
> > With that commit reverted, I see no more I/O errors, only oom-killer
> > messages (which is OK IMO, provided I write 1G of urandom on a machine w/
> > 800M of RAM):
> 
> Hmm... So handle allocation always succeeds in the slow path? (when we
> try to allocate it second time)

Yeah I can see how handle re-allocation with direct reclaim can make it more
successful, but in exchange it oom-kills some user-space process, I suppose.
Is oom-kill really a good alternative though?