Re: [patch] compress the stack layout of do_page_fault(), x86

From: randy_dunlap
Date: Sat Jul 09 2005 - 11:46:46 EST


On Sat, 9 Jul 2005 17:29:24 +0200 Ingo Molnar wrote:

|
| Guillaume noticed a bug in the patch, si_signo should be used instead of
| SIGSEGV. (doh) New patch below.
|
| Ingo
|
| -----
|
| this patch pushes the creation of a rare signal frame (SIGBUS or
| SIGSEGV) into a separate function, thus saving stackspace in the main
| do_page_fault() stackframe. The effect is 132 bytes less of stack used
| by the typical do_page_fault() invocation - resulting in a denser
| cache-layout.
|
| (another minor effect is that in case of kernel crashes that come from a
| pagefault, we add less space to the already existing frame, giving the
| crash functions a slightly higher chance to do their stuff without
| overflowing the stack.)
|
| (the changes also result in slightly cleaner code.)
|
| build and boot tested.

Hi Ingo-

Just to clarify this, "boot tested" does not mean that this
changed code was tested, right?
or do you have a test case that was tested?

Thanks,
---
~Randy
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