[PATCH] signal_struct slab cache

[Mark Hemment]

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.
  Send mail to [e-mail] for more info.

--168455872-729718577-965654574=:21086
Content-Type: TEXT/PLAIN; charset=US-ASCII

Linus, all,

  The per-task signal handling structure (signal_struct) is a "bad" size
for the general sized slab caches; on IA32, it is 1312bytes which means it
comes from the 2048 byte cache - giving only 2 structures from each 
page.  It is probably a bad size for many other architectures.

  By creating a specific slab cache for the signal_struct gives 3
structures per page, saving memory.  Also, by using a specific cache,
allocation and release of the structures is slightly fast.

  Please find a patch (against 2.4.0-test5) attached.

Mark

--168455872-729718577-965654574=:21086
Content-Type: TEXT/PLAIN; charset=US-ASCII; name="signal.markhe.patch"
Content-ID: <Pine.LNX.4.21.0008071422540.21086@alloc>
Content-Description: signal.markhe.patch
Content-Disposition: attachment; filename="signal.markhe.patch"
Content-Transfer-Encoding: BASE64
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--168455872-729718577-965654574=:21086--