lkml.org 
[lkml]   [2001]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Significant performace improvements on reiserfs systems, kupdated bugfixes
On Sun, 23 Sep 2001, Beau Kuiper wrote:

> > Be careful! MTAs rely on this behaviour on fsync(). The official
> > consensus on ReiserFS and ext3 on current Linux 2.4.x kernels (x >= 9)
> > is that "any synchronous operation flushes all pending operations", and
> > if that is changed, you MUST make sure that the changed ReiserFS/ext3fs
> > still make all the guarantees that softupdated BSD file systems make,
> > lest you want people to run their mail queues off "sync" disks.
>
> This code change does not affect the functionality of fsync(), only
> kupdated. kupdated is responsible for flushing buffers that have been
> sitting around too long to disk.

Sorry, I didn't grok that when writing my previous mail in this thread.
I thought kupdate was the one that writes ReiserFS transactions, but
that's kreiserfsd, I think.

> > Note also, if these blocks belong to newly-opened files, you definitely
> > want kupdated to flush these to disk on its next run so that the files
> > are still there after a crash.
>
> They still are (they would be flushed out by the sync_inodes call in
> sync_old_buffers. But why are the file records for any new file more
> important than changes to old files? (This is what an application can
> determince, the kernel should just do what the app says, and treat
> everything else fairly)

Not really, but open is a directory operation, while writing is a file
operation. Directory operations have been flushed earlier traditionally
(5s vs. 30s).

--
Matthias Andree

"Those who give up essential liberties for temporary safety deserve
neither liberty nor safety." - Benjamin Franklin
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:03    [W:0.055 / U:7.812 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site