Re: Limit hash table size

[Andi Kleen <ak@suse.de>]

On Wed, 04 Feb 2004 22:06:42 -0600
Steve Lord <lord@xfs.org> wrote:


> It does look like 2.6 does better, but I don't have quite the
> amount of memory on my laptop....

I see the problem on a 8GB x86-64 box with 2.6.2-rc1. 

After a find / I have:

 Active / Total Objects (% used)    : 1794827 / 1804510 (99.5%)
 Active / Total Slabs (% used)      : 125647 / 125647 (100.0%)
 Active / Total Caches (% used)     : 71 / 112 (63.4%)
 Active / Total Size (% used)       : 685008.27K / 686856.36K (99.7%)
 Minimum / Average / Maximum Object : 0.02K / 0.38K / 128.00K

  OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME                   
708600 708559  99%    0.25K  47240       15    188960K dentry_cache
624734 624128  99%    0.69K  56794       11    454352K reiser_inode_cache
254200 253514  99%    0.09K   6355       40     25420K buffer_head
109327 109253  99%    0.06K   1853       59      7412K size-64

Now I allocate 6GB of RAM. After that:

 Active / Total Objects (% used)    : 741266 / 1092573 (67.8%)
 Active / Total Slabs (% used)      : 78291 / 78291 (100.0%)
 Active / Total Caches (% used)     : 71 / 112 (63.4%)
 Active / Total Size (% used)       : 339837.24K / 455189.93K (74.7%)
 Minimum / Average / Maximum Object : 0.02K / 0.42K / 128.00K

  OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME                   
464497 381126  82%    0.69K  42227       11    337816K reiser_inode_cache
391545 192481  49%    0.25K  26103       15    104412K dentry_cache
135840  95304  70%    0.09K   3396       40     13584K buffer_head

1GB of dentry cache seems to be quite excessive.

-Andi