Re: [PATCH 0/1] mm, shmem: map few pages around fault address if they are in page cache
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2014-02-28 22:34:40
Also in:
linux-fsdevel, lkml
On Fri, 28 Feb 2014 14:18:50 -0800 Ning Qu [off-list ref] wrote:
This is a follow-up patch for "mm: map few pages around fault address if they are in page cache" 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
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?
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-- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>