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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Fri, 14 Aug 2020 10:26:23 +0800 From: Zhaoyang Huang <huangzhaoyang@...il.com> To: Matthew Wilcox <willy@...radead.org> Cc: Roman Gushchin <klamm@...dex-team.ru>, Andrew Morton <akpm@...ux-foundation.org>, Zhaoyang Huang <zhaoyang.huang@...soc.com>, "open list:MEMORY MANAGEMENT" <linux-mm@...ck.org>, LKML <linux-kernel@...r.kernel.org> Subject: Re: [PATCH] mm : update ra->ra_pages if it's NOT equal to bdi->ra_pages On Fri, Aug 14, 2020 at 10:20 AM Zhaoyang Huang <huangzhaoyang@...il.com> wrote: > > On Fri, Aug 14, 2020 at 10:07 AM Matthew Wilcox <willy@...radead.org> wrote: > > > > On Fri, Aug 14, 2020 at 02:43:55AM +0100, Matthew Wilcox wrote: > > > On Fri, Aug 14, 2020 at 09:30:11AM +0800, Zhaoyang Huang wrote: > > > > file->f_ra->ra_pages will remain the initialized value since it opend, which may > > > > be NOT equal to bdi->ra_pages as the latter one is updated somehow(etc, > > > > echo xxx > /sys/block/dm/queue/read_ahead_kb).So sync ra->ra_pages to the > > > > updated value when sync read. > > > > > > It still ignores the work done by shrink_readahead_size_eio() > > > and fadvise(POSIX_FADV_SEQUENTIAL). > > > > ... by the way, if you're trying to update one particular file's readahead > > state, you can just call fadvise(POSIX_FADV_NORMAL) on it. > > > > If you want to update every open file's ra_pages by writing to sysfs, > > then just no. We don't do that. > No, What I want to fix is the file within one process's context keeps > using the initialized value when it is opened and not sync with new > value when bdi->ra_pages changes. So you mean it is just the desired behavior as having the opened file use the initialized value even if bdi->ra_pages changed via sysfs? > > > > You haven't said what problem you're facing, so I really can't be more > > helpful.
Powered by blists - more mailing lists