lkml.org 
[lkml]   [2009]   [Apr]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Ext4 and the "30 second window of death"
On Wed, Apr 01, 2009 at 06:20:50AM +0100, Sitsofe Wheeler wrote:

> Just out of curiosity, when laptop mode is happening is there a
> guarantee that writes to other files won't be reordered to before the
> fsync?

laptop-mode does two things - tweak the dirty page semantics slightly
(not in an interestingly relevant way) and call sys_sync() a few seconds
after something hits disk rather than cache. In contrast to Ted's
suggestion that laptop-mode reduces data integrity, it actually enhances
it by opportunistically ensuring that data hits disk. It's the
lengthening of the commit intervals that usually accompanies it that
increases the risk of data loss.

--
Matthew Garrett | mjg59@srcf.ucam.org


\
 
 \ /
  Last update: 2009-04-01 17:15    [W:0.095 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site