lkml.org 
[lkml]   [2008]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: How to find out, what "pdflush" is working on
Martin Knoblauch wrote:
> Hi,
>
> I find the following comment in mm/pdflush.c
>
> /* * The pdflush threads are worker threads for writing back dirty data. *
> Ideally, we'd like one thread per active disk spindle. But the disk *
> topology is very hard to divine at this level. Instead, we take * care in
> various places to prevent more than one pdflush thread from * performing
> writeback against a single filesystem. pdflush threads * have the PF_FLUSHER
> flag set in current->flags to aid in this. */
>
> Is there a way to find out what a certain instance of "pdflush" is working
> on? Like which block-device or which fliesystem it is writing to? I am still
> (2.6.27) trying to track down why writing a single file can make linux very
> sluggish and unresponsive. If that happens I usually see all possible 8
> "pdflush" threads being in "D"-state. According to above comment only one of
> them should be really busy.

The key word is "ideally". We'd like it to work that way, but it doesn't.
Patches to fix this are welcome.

-- Chris


\
 
 \ /
  Last update: 2008-09-16 21:13    [W:0.933 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site