Re: AGP PAT issue.

From: Ingo Molnar
Date: Thu Sep 11 2008 - 04:17:41 EST

* Rene Herman <rene.herman@xxxxxxxxxxxx> wrote:

> On 22-08-08 22:02, Rene Herman wrote:
>> On 22-08-08 06:15, Ingo Molnar wrote:
>>> The frontside cache itself is in x86/urgent:
>>> # 80c5e73: x86: fix Xorg startup/shutdown slowdown with PAT
>>> ... and should at least solve the symptom that you've hit in practice
>>> (the slowdown), without changing the underlying PAT machinery. (which
>>> would be way too dangerous for v2.6.27)
>> Well, please note that that specific commit only fixes X startup -- it
>> doesn't do anything for shutdown. With only that one, I'm still at 14
>> seconds for X shutdown (first time after boot that is, 5 seconds
>> subsequent shutdowns) versus 1 (or sub 1, feels immediate) normally.
>> It's also a black-screen "hang", so we'll probably be getting a lot of
>> "long hang at shutdown" reports without something additionally for .27.
>> Venki?
> Haven't been subcribed to any lists recently and someone was talking
> about "the other thread" before but just noticed that an -rc6 was cut.
> Please note that the shutdown issue remains unfixed in it (I'm doing
> my coalescing changes locally).

here's what is pending in tip/x86/pat for v2.6.28:

110e035: x86: make sure the CPA test code's use of _PAGE_UNUSED1 is obvious
c09ff7e: linux-next: fix x86 tree build failure
01de05a: x86: have set_memory_array_{uc,wb} coalesce memtypes, fix
5f310b6: agp: enable optimized agp_alloc_pages methods
c5e147c: x86: have set_memory_array_{uc,wb} coalesce memtypes.
9a79f4f: x86: {reverve,free}_memtype() take a physical address
8b53b57: Merge branch 'x86/urgent' into x86/pat
ab7e792: x86: fix pageattr-test
bd07928: agp: add agp_generic_destroy_pages()
37acee1: agp: generic_alloc_pages()
d75586a: x86, pageattr: introduce APIs to change pageattr of a page array
cacf890: Revert "introduce two APIs for page attribute"
9326d61: Revert "reduce tlb/cache flush times of agpgart memory allocation"
5843d9a: x86, pat: avoid highmem cache attribute aliasing
466ae83: reduce tlb/cache flush times of agpgart memory allocation
1ac2f7d: introduce two APIs for page attribute
012f09e: x86: compile pat debugfs interface only if CONFIG_X86_PAT is set

that includes your coalescing optimizations and fixes. None of that is
really v2.6.27 material i think.

Btw., if you track -tip as per:

you can merge these changes alone into latest -git just by doing:

git merge tip/x86/pat

or you can use tip/master for the full range of pending features and

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