[RFC] [PATCH 0/9] remove page_cgroup pointer (with some enhancements)

KAMEZAWA Hiroyuki
2008-09-11T11:08:14Z

Hi, Balbir.

I wrote remove-page-cgroup-pointer patch on top of my small patches.
This series includes enhancements patches for memory resource controller
on my queue.

I think I can (or have to) do more twaeks but post this while it's hot.
Passed some tests.

remove-page-cgroup-pointer patch is [8/9] and [9/9].
How about this ?

Peformance comparison is below.
==
rc5-mm1
==
Execl Throughput 3006.5 lps (29.8 secs, 3 samples)
C Compiler Throughput 1006.7 lpm (60.0 secs, 3 samples)
Shell Scripts (1 concurrent) 4863.7 lpm (60.0 secs, 3 samples)
Shell Scripts (8 concurrent) 943.7 lpm (60.0 secs, 3 samples)
Shell Scripts (16 concurrent) 482.7 lpm (60.0 secs, 3 samples)
Dc: sqrt(2) to 99 decimal places 124804.9 lpm (30.0 secs, 3 samples)

After this series
==
Execl Throughput 3003.3 lps (29.8 secs, 3 samples)
C Compiler Throughput 1008.0 lpm (60.0 secs, 3 samples)
Shell Scripts (1 concurrent) 4580.6 lpm (60.0 secs, 3 samples)
Shell Scripts (8 concurrent) 913.3 lpm (60.0 secs, 3 samples)
Shell Scripts (16 concurrent) 569.0 lpm (60.0 secs, 3 samples)
Dc: sqrt(2) to 99 decimal places 124918.7 lpm (30.0 secs, 3 samples)

Hmm..no loss ? But maybe I should find what I can do to improve this.

Brief patch description is below.

1. patches/nolimit_root.patch
This patch makes 'root' cgroup's limit to be fixed to unlimited.

2. patches/atomic_flags.patch
This patch makes page_cgroup->flags to be unsigned long and add atomic ops.

3. patches/account_move.patch
This patch implements move_account() function for recharging account
from a memory resource controller to another.

4. patches/new_force_empty.patch
This patch makes force_empty() to use move_account() rather than just drop
accounts. (As fist step, account is moved to 'root'. We can change this later.)

5. patches/make_mapping_null.patch
Clean up. This guarantees page->mapping to be NULL before uncharge() against
page cache is called.

6. patches/stat.patch
Optimize page_cgroup_change_statistics().

7. patches/charge-will-success.patch
Add "likely" to charge function.

8. patches/page_cgroup.patch
remove page_cgroup pointer from struct page and add lookup-system for
page_cgroup from pfn,

9. patches/boost_page_cgroup_lookupg.patch
user per-cpu cache for fast access to page_cgroup.

Thanks,
-Kame