Messages in this thread |  | | From | Gene Heskett <> | Subject | Re: Possible dcache BUG | Date | Wed, 11 Aug 2004 22:23:50 -0400 |
| |
On Wednesday 11 August 2004 21:26, Nick Piggin wrote: >Gene Heskett wrote: >>On Wednesday 11 August 2004 01:15, Linus Torvalds wrote: >>>On Tue, 10 Aug 2004, Linus Torvalds wrote: >>>>So I suspect it's a balancing issue. Possibly just the slight >>>>change in slab balancing to fix the highmem problems. Maybe we >>>>shrink slab _too_ aggressively or something. >>> >>>Udo, that's a simple thing to check. If it's the slab balancing >>>changes, then you should be able to test it with just a >>> >>> bk cset -x1.1830.4.3 >>> >>>if you have the current BK and are a BK user, or by just revertign >>>the patch here ("patch -R -p1" from inside your linux source tree) >>>if you're not a BK user.. >>> >>> Linus >> >>With the previously attached patch reverted, a fresh kernel builds >> in: real 7m18.296s >>user 5m49.385s >>sys 0m31.760s >>which is a marked improvement, but still about 1m30 or so slow. > >This could easily be from too much slab pressure. How much memory do > you have?
1 Gb in 2 512Mb sticks of DDR400 ram which signs on in the bios as dual channel. The sticks are in the first and third slots as recommended by the mobo docs.
>Have you got highmem turned on? Yes
>The new slab pressure calculation is an improvement in that it won't > let slab >get out of control and cause OOMs, however it can shrink the slab > too much. If you regularly need ZONE_DMA pages, for example. AFAIKS > there isn't much you >can do about this except go to per-zone slab LRUs.
And how would an otherwise clueless user like me determine that?
>That said, your stability problems should be resolved first. If they > are fixed,
Which as yet is an unknown, Nick. Uptime now at 22:15:14 up 12:30, 5 users, load average: 1.03, 1.11, 1.05
>and you would like to help track down the slowdown, run the kernel >compile about >3 times each with and without the patch, and save cat /proc/vmstat >before and >after each compile. Try to keep all else constant.
I'll try that if I get to a 30+ hour uptime.
>Thanks >Nick
-- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) 99.24% setiathome rank, not too shabby for a WV hillbilly Yahoo.com attorneys please note, additions to this message by Gene Heskett are: Copyright 2004 by Maurice Eugene Heskett, all rights reserved. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |