Re: 2.4.16 memory badness (fixed?)

From: Ken Brownfield (brownfld@irridia.com)
Date: Mon Dec 10 2001 - 02:24:08 EST

What about moving the calls to shrink_[di]cache_memory() after the
nr_pages check after the call to kmem_cache_reap? Or perhaps keep it at
the beginning, but only call it after priority has gone a number of
notches down from DEF_PRIORITY?

Something like that seems like the only obvious way to balance how soon
these caches are flushed without over- or under-kill.

Also, shouldn't shrink_dqcache_memory use priority rather than
DEF_PRIORITY? I'm also not sure what the reasoning is behind the
nr_pages=chunk_size reset.

In the case that Leigh and I are seeing (and my readprofile runs) it
sounds like shrink_cache is getting called a ton, while the bloated d/i
caches are flushed too little, too late.

Just $0.02 from a newby. ;)

Thanks for the tip, Mike, 

-- 
Ken.
brownfld@irridia.com

On Sun, Dec 09, 2001 at 06:17:11PM +0100, Mike Galbraith wrote:
| On Sun, 9 Dec 2001, Leigh Orf wrote:
| 
| > In a personal email, Mike Galbraith wrote to me:
| >
| > |   On Sat, 8 Dec 2001, Leigh Orf wrote:
| > |
| > |   > inode_cache       439584 439586    512 62798 62798    1
| > |   > dentry_cache      454136 454200    128 15140 15140    1
| > |
| > |   I'd try moving shrink_[id]cache_memory to the very top of vmscan.c::shrink_caches.
| > |
| > |   	-Mike
| >
| > Mike,
| >
| > I tried what you suggested starting with a stock 2.4.16 kernel, and it
| > did fix the problem with 2.4.16 ENOMEM being returned.
| >
| > Now with that change and after updatedb runs, here's what the memory
| > situation looks like. Note inode_cache and dentry_cache are almost
| > nothing. Dunno if that's a good thing or not, but I'd definitely
| 
| Almost nothing isn't particularly good after updatedb ;-)
| 
| > consider this for a patch.
| 
| No, but those do need faster pruning imho.  The growth rate can be
| really really fast at times.
| 
| 	-Mike
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This archive was generated by hypermail 2b29 : Sat Dec 15 2001 - 21:00:16 EST