Re: Possible performance problem introduced between kernel 2.6.15 and 2.6.17 on xfs code

[fdegrassi <francesco.degrassi@emaze.net>]

The specific problem is related to gnome point-n-click only.
Anyway, I could be wrong, but i don't think it is a bug in gnome because:
1. it affects specifically local XFS filesystems only
2. the problem is not present on kernel 2.6.15 (I tested 2.6.17 and 
2.6.15, both on ubuntu 6.10)
3. the problem does not manifest if i disable the call to 
gnome_vfs_forget_cache, that, for what i understand, simply calls 
fadvice POSIX_FADV_DONTNEED.

More info can be found on gnome bugzilla entry.
Francesco Degrassi


Eric Sandeen wrote:
> fdegrassi wrote:
>> Hi all,
>> i noticed that changing from kernel 2.6.15 to 2.6.17, gnomevfs-copy 
>> operations suffered an heavy performance hit (20 times slower).
>> I checked quickly (i am not a kernel hacker) and i think it could be 
>> related to libgnomevfs calling fadvice POSIX_FADV_DONTNEED  (in 
>> gnome_vfs_forget_cache, disabling this behaviour gets back normal 
>> performance).
>> I am not able to dig deeper than this, anyway it could be a starting 
>> point.
>> The relevant gnome bugzilla reference is the following: 
>> http://bugzilla.gnome.org/show_bug.cgi?id=363400
>>
>> Francesco Degrassi
>>
>>
>
> Is a copy command from the shell affected, or just gnome point-n-click?
>
> -Eric