linux-kernel - Re: [PATCH] sbitmap: fix possible io hung due to lost wakeup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20220908093330.lzynnuqlnvppj27q@quack3>
Date:   Thu, 8 Sep 2022 11:33:30 +0200
From:   Jan Kara <jack@...e.cz>
To:     Keith Busch <kbusch@...nel.org>
Cc:     Jan Kara <jack@...e.cz>, Yu Kuai <yukuai1@...weicloud.com>,
        axboe@...nel.dk, osandov@...com, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, yukuai3@...wei.com,
        yi.zhang@...wei.com
Subject: Re: [PATCH] sbitmap: fix possible io hung due to lost wakeup

On Wed 07-09-22 12:20:09, Keith Busch wrote:
> On Wed, Sep 07, 2022 at 06:41:50PM +0200, Jan Kara wrote:
> > On Wed 07-09-22 08:13:40, Keith Busch wrote:
> > > 
> > > I'm not sure about this part. We've already decremented, so the freed bit is
> > > accounted for against the batch. Returning true here may double-count the freed
> > > bit, right?
> > 
> > Yes, we may wake up waiters unnecessarily frequently. But that's a
> > performance issue at worst and only if it happens frequently. So I don't
> > think it matters in practice (famous last words ;).
> 
> Ok, let's go with that. Do you want to send the patch? I have a follow-up fix
> for batched tagging that depends on this.

I think Kuai will do that. But if not, I can certainly take his patch and
resubmit it with the fixup.

								Honza
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR