Re: [PATCH 0/1] mm, shmem: map few pages around fault address if they are in page cache

let me double check.

Best wishes,
-- 
Ning Qu (曲宁) | Software Engineer | quning@google.com | +1-408-418-6066


On Fri, Feb 28, 2014 at 2:34 PM, Andrew Morton [off-list ref]wrote:

On Fri, 28 Feb 2014 14:18:50 -0800 Ning Qu [off-list ref] wrote:

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This is a follow-up patch for "mm: map few pages around fault address if

they are in page cache"

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We use the generic filemap_map_pages as ->map_pages in shmem/tmpfs.

Please cc Hugh on shmem/tmpfs things

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=========================================================================
Below is just some simple experiment numbers from this patch, let me

know if

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you would like more:

Tested on Xeon machine with 64GiB of RAM, using the current default fault
order 4.

Sequential access 8GiB file
                      Baseline        with-patch
1 thread
    minor fault               205             101

Confused.  Sequential access of an 8G file should generate 2,000,000
minor faults, not 205.  And with FAULT_AROUND_ORDER=4, that should come
down to 2,000,000/16 minor faults when using faultaround?

quoted

    time, seconds     7.94            7.82

Random access 8GiB file
                      Baseline        with-patch
1 thread
    minor fault               724             623
    time, seconds     9.75            9.84