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Groups > linux.kernel > #1482847
| From | "Chen, Tim C" <tim.c.chen@intel.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | RE: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out |
| Date | 2016-09-14 02:00 +0200 |
| Message-ID | <sh5Mm-t4-11@gated-at.bofh.it> (permalink) |
| References | (3 earlier) <sgPex-6r3-5@gated-at.bofh.it> <sgPHz-6Bw-15@gated-at.bofh.it> <sgQ0W-6Y0-29@gated-at.bofh.it> <sgRJp-7Xu-43@gated-at.bofh.it> <sgS2J-8jW-15@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
>>
>> - Avoid CPU time for splitting, collapsing THP across swap out/in.
>
>Yes, if you want, please give us how bad it is.
>
It could be pretty bad. In an experiment with THP turned on and we
enter swap, 50% of the cpu are spent in the page compaction path.
So if we could deal with units of large page for swap, the splitting
and compaction of ordinary pages to large page overhead could be avoided.
51.89% 51.89% :1688 [kernel.kallsyms] [k] pageblock_pfn_to_page
|
--- pageblock_pfn_to_page
|
|--64.57%-- compaction_alloc
| migrate_pages
| compact_zone
| compact_zone_order
| try_to_compact_pages
| __alloc_pages_direct_compact
| __alloc_pages_nodemask
| alloc_pages_vma
| do_huge_pmd_anonymous_page
| handle_mm_fault
| __do_page_fault
| do_page_fault
| page_fault
| 0x401d9a
|
|--34.62%-- compact_zone
| compact_zone_order
| try_to_compact_pages
| __alloc_pages_direct_compact
| __alloc_pages_nodemask
| alloc_pages_vma
| do_huge_pmd_anonymous_page
| handle_mm_fault
| __do_page_fault
| do_page_fault
| page_fault
| 0x401d9a
--0.81%-- [...]
Tim
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Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-09 22:40 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-13 08:20 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-13 08:50 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-13 09:10 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-13 11:00 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-13 11:20 +0200
RE: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Chen, Tim C" <tim.c.chen@intel.com> - 2016-09-14 02:00 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-19 09:20 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Tim Chen <tim.c.chen@linux.intel.com> - 2016-09-19 18:00 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-18 04:00 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-19 09:10 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-20 05:00 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out "Huang\, Ying" <ying.huang@intel.com> - 2016-09-20 07:30 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Minchan Kim <minchan@kernel.org> - 2016-09-20 07:40 +0200
Re: [PATCH -v3 00/10] THP swap: Delay splitting THP during swapping out Andrea Arcangeli <aarcange@redhat.com> - 2016-09-13 16:40 +0200
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