The patch titled
readahead: context based method - apply stream_shift size limits to contexta method
has been removed from the -mm tree. Its filename is
readahead-context-based-method-apply-stream_shift-size-limits-to-contexta-method.patch
This patch was dropped because it was folded into readahead-context-based-method.patch
------------------------------------------------------
Subject: readahead: context based method - apply stream_shift size limits to contexta method
From: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Apply size limits to the contexta method, so that the possible following
stateful method will not be presented too small stream_shift size.
Signed-off-by: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/readahead.c | 20 ++++++++------------
1 file changed, 8 insertions(+), 12 deletions(-)
diff -puN mm/readahead.c~readahead-context-based-method-apply-stream_shift-size-limits-to-contexta-method mm/readahead.c
--- devel/mm/readahead.c~readahead-context-based-method-apply-stream_shift-size-limits-to-contexta-method 2006-06-09 01:22:45.000000000 -0700
+++ devel-akpm/mm/readahead.c 2006-06-09 01:22:45.000000000 -0700
@@ -1389,13 +1389,12 @@ out_unlock:
* Determine the request parameters for context based read-ahead that extends
* from start of file.
*
- * The major weakness of stateless method is perhaps the slow grow up speed of
- * ra_size. The logic tries to make up for this in the important case of
- * sequential reads that extend from start of file. In this case, the ra_size
- * is not chosen to make the whole next chunk safe (as in normal ones). Only
- * half of which is safe. The added 'unsafe' half is the look-ahead part. It
- * is expected to be safeguarded by rescue_pages() when the previous chunks are
- * lost.
+ * One major weakness of stateless method is the slow scaling up of ra_size.
+ * The logic tries to make up for this in the important case of sequential
+ * reads that extend from start of file. In this case, the ra_size is not
+ * chosen to make the whole next chunk safe (as in normal ones). Only part of
+ * which is safe: the tailing look-ahead part is 'unsafe'. However it will be
+ * safeguarded by rescue_pages() when the previous chunks are lost.
*/
static int adjust_rala_aggressive(unsigned long ra_max,
unsigned long *ra_size, unsigned long *la_size)
@@ -1407,11 +1406,6 @@ static int adjust_rala_aggressive(unsign
*la_size = index * readahead_ratio / 100;
*ra_size += *la_size;
- if (*ra_size > ra_max)
- *ra_size = ra_max;
- if (*la_size > *ra_size)
- *la_size = *ra_size;
-
return 1;
}
@@ -1475,6 +1469,8 @@ try_context_based_readahead(struct addre
ra_set_class(ra, RA_CLASS_CONTEXT);
}
+ limit_rala(ra_max, ra_index - index, &ra_size, &la_size);
+
ra_set_index(ra, index, ra_index);
ra_set_size(ra, ra_size, la_size);
_
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.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-call-scheme-no-fastcall-for-readahead_cache_hit-kconfig-option-readahead_hit_feedback.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-remove-the-size-limit-of-max_sectors_kb-on-read_ahead_kb.patch
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