Re: Limit hash table size

Maneesh Soni
2004-02-06T05:30:41Z

On Fri, Feb 06, 2004 at 04:49:01AM +0000, Andi Kleen wrote:
> 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.
>

Here dentry cache looks to be approximately 104 MB (104,412K) and not 1GB and
it has reduced from 188 MB to 104 MB.

Maneesh

--
Maneesh Soni
Linux Technology Center,
IBM Software Lab, Bangalore, India
email: maneesh@in.ibm.com
Phone: 91-80-5044999 Fax: 91-80-5268553
T/L : 9243696