Re: [PATCH] fix return value for mb_cache_shrink_fn when nr_to_scan > 0

[shenghui <crosslonelyover@gmail.com>]

2010/7/20 Andreas Gruenbacher <agruen@suse.de>:
> On Sunday 18 July 2010 08:36:59 Wang Sheng-Hui wrote:
>> I regenerated the patch. Please check it.
>
> The logic for calculating how many objects to free is still wrong:
> mb_cache_shrink_fn returns the number of entries scaled by
> sysctl_vfs_cache_pressure / 100.  It should also scale nr_to_scan by the
> inverse of that.  The sysctl_vfs_cache_pressure == 0 case (never scale) may
> require special attention.
>
> See dcache_shrinker() in fs/dcache.c.
>
> Thanks,
> Andreas
>

Sorry, I haven't found any special attention on
sysctl_vfs_cache_pressure == 0 case or scale
nr_to_scan in fs/dcache.c

 900static int shrink_dcache_memory(int nr, gfp_t gfp_mask)
 901{
 902        if (nr) {
 903                if (!(gfp_mask & __GFP_FS))
 904                        return -1;
 905                prune_dcache(nr);
 906        }
 907        return (dentry_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
 908}




-- 


Thanks and Best Regards,
shenghui

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>