Messages in this thread | | | Date | Mon, 28 Dec 2009 10:19:02 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC PATCH] asynchronous page fault. |
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On Mon, 28 Dec 2009 09:36:06 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> == one vma == > # Samples: 1338964273489 > # > # Overhead Command Shared Object Symbol > # ........ ............... ........................ ...... > # > 26.90% multi-fault-all [kernel] [k] clear_page_c > | > --- clear_page_c > __alloc_pages_nodemask > handle_mm_fault > do_page_fault > page_fault > 0x400940 > | > --100.00%-- (nil) > > 20.65% multi-fault-all [kernel] [k] _raw_spin_lock > | > --- _raw_spin_lock > | > |--85.07%-- free_pcppages_bulk > | free_hot_cold_page > > ....<snip> > 3.94% multi-fault-all [kernel] [k] find_vma_speculative > | > --- find_vma_speculative > | > |--99.40%-- do_page_fault > | page_fault > | 0x400940 > | | > | --100.00%-- (nil) > | > --0.60%-- page_fault > 0x400940 > | > --100.00%-- (nil) > == > A small modification for avoiding atomic_add_unless() makes following score. (used atomic_inc()->atomic_read() instead of that.) == 2.55% multi-fault-all [kernel] [k] vma_put | --- vma_put | |--98.87%-- do_page_fault | page_fault | 0x400940 | (nil) | --1.13%-- page_fault 0x400940 (nil) 0.65% multi-fault-all [kernel] [k] find_vma_speculative | --- find_vma_speculative | |--95.55%-- do_page_fault | page_fault | 0x400940 | | | --100.00%-- (nil) | --4.45%-- page_fault 0x400940 (nil) == Hmm...maybe worth to consider some. I hope something good pops up to me after new year vacation.
Regards, -Kame
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