[PATCH 00/11] 512K readahead size with thrashing safe readahead

[Wu Fengguang <fengguang.wu@intel.com>]

Andrew,

It seems there are no strong objections against the 512KB readahead size.
(Or, anyone would prefer an 1MB readahead? Chris Mason picked a 4MB size
 for btrfs after all.)

So would you include the patchset for wider tests in -mm? I reordered the
patchset a bit: the first 2 patches are good candidates for 2.6.34, while
the others may need longer tests.

Changes since RFC:
- move the lenthy intro text to individual patch changelogs
- treat get_capacity()==0 as uninitilized value (Thanks to Vivek Goyal)
- increase readahead size limit for small devices (Thanks to Jens Axboe)
- add fio test results by Vivek Goyal

	[PATCH 01/11] readahead: limit readahead size for small devices
	[PATCH 02/11] readahead: retain inactive lru pages to be accessed soon

	[PATCH 03/11] readahead: bump up the default readahead size
	[PATCH 04/11] readahead: introduce {MAX|MIN}_READAHEAD_PAGES macros for ease of use
	[PATCH 05/11] readahead: replace ra->mmap_miss with ra->ra_flags
	[PATCH 06/11] readahead: thrashing safe context readahead
	[PATCH 07/11] readahead: record readahead patterns
	[PATCH 08/11] readahead: add tracing event
	[PATCH 09/11] readahead: add /debug/readahead/stats
	[PATCH 10/11] readahead: dont do start-of-file readahead after lseek()
	[PATCH 11/11] radixtree: speed up next/prev hole search

Thanks,
Fengguang