Re: Limit hash table size

Andi Kleen
2004-02-06T04:46:59Z

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