* Seigo Tanimura <[EMAIL PROTECTED]> [010413 02:39] wrote:
> On Thu, 12 Apr 2001 22:50:50 +0200,
> Poul-Henning Kamp <[EMAIL PROTECTED]> said:
>
> Poul-Henning> We keep namecache entries around as long as we can use them, and that
> Poul-Henning> generally means that recreating them is a rather expensive operation,
> Poul-Henning> involving creation of vnode and very likely a vm object again.
>
> Holding a namecache entry forever until its vnode is reused results in
> disaster when a huge number of files are accessed concurrently, causing
> active vnodes to eat up all of memory. This beast killed a box of mine
> with 3GB of memory and 200GB of a RAID0 disk array serving about
> 300,000 files by cvsupd and making the world a few months ago, when
> the number of the vnodes reached around 400,000 to make all of the
> processes wait for a free vnode.
>
> With a help by tegge, the box is now reclaiming directory vnodes when
> few free vnodes are available. Only directory vnodes holding no child
> directory vnodes held in v_cache_src are recycled, so that directory
> vnodes near the root of the filesystem hierarchy remain in namecache
> and directory vnodes are not reclaimed in cascade. The number of
> vnodes in the box is now about 135,000, staying quite steadily.
>
> Name'cache' is the place to hold vnodes for future use which may *not*
> come, hence vnodes held in namecache should be reclaimed in case of
> critical vnode shortage.
Are these changes planned for integration?
--
-Alfred Perlstein - [[EMAIL PROTECTED]|[EMAIL PROTECTED]]
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