The patch titled
readahead: context based method - slow start
has been added to the -mm tree. Its filename is
readahead-context-based-method-slow-start.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: readahead: context based method - slow start
From: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
The context method will lead to noticable overhead on sparse random reads.
Having the readahead window to start slowly makes it much better.
Signed-off-by: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/readahead.c | 5 +++++
1 file changed, 5 insertions(+)
diff -puN mm/readahead.c~readahead-context-based-method-slow-start mm/readahead.c
--- a/mm/readahead.c~readahead-context-based-method-slow-start
+++ a/mm/readahead.c
@@ -1439,6 +1439,11 @@ try_context_based_readahead(struct addre
return -1;
} else if (prev_page || probe_page(mapping, index - 1)) {
ra_index = index;
+ /*
+ * Slow start of readahead window.
+ * It helps avoid most readahead miss on sparse random reads.
+ */
+ ra_min = readahead_hit_rate;
} else if (readahead_hit_rate > 1) {
ra_index = find_segtail_backward(mapping, index,
readahead_hit_rate + ra_min);
_
Patches currently in -mm which might be from wfg@xxxxxxxxxxxxxxxx are
origin.patch
readahead-kconfig-options.patch
radixtree-introduce-radix_tree_scan_hole.patch
mm-introduce-probe_page.patch
mm-introduce-pg_readahead.patch
readahead-add-look-ahead-support-to-__do_page_cache_readahead.patch
readahead-delay-page-release-in-do_generic_mapping_read.patch
readahead-insert-cond_resched-calls.patch
readahead-minmax_ra_pages.patch
readahead-events-accounting.patch
readahead-rescue_pages.patch
readahead-sysctl-parameters.patch
readahead-sysctl-parameters-fix.patch
readahead-min-max-sizes.patch
readahead-state-based-method-aging-accounting.patch
readahead-state-based-method-routines.patch
readahead-state-based-method-routines-no-ra_flag_eof-on-single-page-file.patch
readahead-state-based-method.patch
readahead-state-based-method-readahead-state-based-method-stand-alone-size-limit-code.patch
readahead-context-based-method.patch
readahead-context-based-method-apply-stream_shift-size-limits-to-contexta-method.patch
readahead-context-based-method-fix-remain-counting.patch
readahead-context-based-method-slow-start.patch
readahead-initial-method-guiding-sizes.patch
readahead-initial-method-guiding-sizes-aggressive-initial-sizes.patch
readahead-initial-method-thrashing-guard-size.patch
readahead-initial-method-expected-read-size.patch
readahead-initial-method-user-recommended-size.patch
readahead-initial-method.patch
readahead-backward-prefetching-method.patch
readahead-backward-prefetching-method-add-use-case-comment.patch
readahead-seeking-reads-method.patch
readahead-thrashing-recovery-method.patch
readahead-call-scheme.patch
readahead-call-scheme-fix-fastcall.patch
readahead-call-scheme-no-fastcall-for-readahead_cache_hit.patch
readahead-laptop-mode.patch
readahead-loop-case.patch
readahead-nfsd-case.patch
readahead-turn-on-by-default.patch
readahead-debug-radix-tree-new-functions.patch
readahead-debug-traces-showing-accessed-file-names.patch
readahead-debug-traces-showing-read-patterns.patch
readahead-remove-size-limit-on-read_ahead_kb.patch
readahead-backward-prefetching-method-fix.patch
readahead-kconfig-option-readahead_allow_overheads.patch
readahead-kconfig-option-readahead_smooth_aging.patch
readahead-kconfig-option-readahead_hit_feedback.patch
readahead-remove-the-size-limit-of-max_sectors_kb-on-read_ahead_kb.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
