linux-kernel - Re: [PATCH -mm -v10 1/3] mm, THP, swap: Delay splitting THP during swap out

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: <20170501104430.GA16306@cmpxchg.org>
Date:   Mon, 1 May 2017 12:44:30 +0200
From:   Johannes Weiner <hannes@...xchg.org>
To:     Minchan Kim <minchan@...nel.org>
Cc:     "Huang, Ying" <ying.huang@...el.com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        Andrea Arcangeli <aarcange@...hat.com>,
        Ebru Akagunduz <ebru.akagunduz@...il.com>,
        Michal Hocko <mhocko@...nel.org>, Tejun Heo <tj@...nel.org>,
        Hugh Dickins <hughd@...gle.com>, Shaohua Li <shli@...nel.org>,
        Rik van Riel <riel@...hat.com>, cgroups@...r.kernel.org
Subject: Re: [PATCH -mm -v10 1/3] mm, THP, swap: Delay splitting THP during
 swap out

On Fri, Apr 28, 2017 at 05:40:44PM +0900, Minchan Kim wrote:
> However, get_swap_page is ugly now. The caller should take care of
> failure and should retry after split. I hope get_swap_page includes
> split and retry logic in itself without reling on the caller.

I think this makes the interface terrible. It's an allocation function
to which you pass a reference object for size - and if the allocation
doesn't succeed it'll split your reference object to make it fit?

That's a nasty side effect for this function to have.