Messages in this thread | | | Date | Mon, 04 Dec 2006 00:57:50 -0500 | From | Wendy Cheng <> | Subject | Re: [PATCH] prune_icache_sb |
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Andrew Morton wrote:
>On Sun, 03 Dec 2006 12:49:42 -0500 >Wendy Cheng <wcheng@redhat.com> wrote: > > > >>I read this as "It is ok to give system admin(s) commands (that this >>"drop_pagecache_sb() call" is all about) to drop page cache. It is, >>however, not ok to give filesystem developer(s) this very same function >>to trim their own page cache if the filesystems choose to do so" ? >> >> > >If you're referring to /proc/sys/vm/drop_pagecache then no, that isn't for >administrators - it's a convenience thing for developers, to get repeatable >benchmarks. Attempts to make it a per-numa-node control for admin purposes have >been rejected. > > Just saw you suggested the "next door" LKML thread ("la la la la ... swappiness") to use "-o sync" ? Well, now I do see you're determined ... anyway, I think I got my stuff working without this kernel patch ... still under testing though.
The rename post will be done first thing tomorrow morning.
>>[snip] ....... >> >> >hmm, I suppose that makes sense. > >Are there dentries associated with these locks? > > Yes, dentries are part of the logic (during lookup time) but book-keepings (reference count, reclaim, delete, etc) are all done thru inode structures.
> > >>>Did you look at improving that lock-lookup algorithm, btw? Core kernel has >>>no problem maintaining millions of cached VFS objects - is there any reason >>>why your lock lookup cannot be similarly efficient? >>> >>> >>> Yes, just found the new DLM uses "jhash" call (include/linux/jhash.h). I'm on an older version of DLM that uses FNV hash algorithm (http://www.isthe.com/chongo/tech/comp/fnv/). Will do some performance test runs to compare these two methods.
A final note on this subject - I may not agree with you (about various things) but your comments and amazingly quick responses are very very appreciated !
-- Wendy
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