Andrew, This introduces the per-cpu readahead stats, tracing, backwards prefetching, fixes context readahead for SSD random reads and does some other minor changes. Changes since v4: - fix changelog for readahead stats Changes since v3: - default to CONFIG_READAHEAD_STATS=n - drop "block: limit default readahead size for small devices" (and expect some distro udev rules to do the job) - use percpu_counter for the readahead stats Changes since v2: - use per-cpu counters for readahead stats - make context readahead more conservative - simplify readahead tracing format and use __print_symbolic() - backwards prefetching and snap to EOF fixes and cleanups Changes since v1: - use bit fields: pattern, for_mmap, for_metadata, lseek - comment the various readahead patterns - drop boot options "readahead=" and "readahead_stats=" - add for_metadata - add snapping to EOF [PATCH 1/9] readahead: make context readahead more conservative [PATCH 2/9] readahead: record readahead patterns [PATCH 3/9] readahead: tag mmap page fault call sites [PATCH 4/9] readahead: tag metadata call sites [PATCH 5/9] readahead: add vfs/readahead tracing event [PATCH 6/9] readahead: add /debug/readahead/stats [PATCH 7/9] readahead: dont do start-of-file readahead after lseek() [PATCH 8/9] readahead: snap readahead request to EOF [PATCH 9/9] readahead: basic support for backwards prefetching fs/Makefile | 1 fs/ext3/dir.c | 1 fs/ext4/dir.c | 1 fs/read_write.c | 3 fs/trace.c | 2 include/linux/fs.h | 41 ++++ include/linux/mm.h | 4 include/trace/events/vfs.h | 78 ++++++++ mm/Kconfig | 15 + mm/filemap.c | 9 - mm/readahead.c | 310 +++++++++++++++++++++++++++++++++-- 11 files changed, 450 insertions(+), 15 deletions(-) Thanks, Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>