From: Wu Fengguang <wfg@mail.ustc.edu.cn>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org, Wu Fengguang <wfg@mail.ustc.edu.cn>
Subject: [PATCH 21/23] readahead: debug radix tree new functions
Date: Sun, 19 Mar 2006 10:34:34 +0800 [thread overview]
Message-ID: <20060319023459.086278000@localhost.localdomain> (raw)
In-Reply-To: <20060319023413.305977000@localhost.localdomain>
[-- Attachment #1: readahead-debug-radix-tree.patch --]
[-- Type: text/plain, Size: 2114 bytes --]
Do some sanity checkings on the newly added radix tree code.
It is meant to be removed after a while.
Signed-off-by: Wu Fengguang <wfg@mail.ustc.edu.cn>
---
mm/readahead.c | 24 ++++++++++++++++++++++++
1 files changed, 24 insertions(+)
--- linux-2.6.16-rc6-mm2.orig/mm/readahead.c
+++ linux-2.6.16-rc6-mm2/mm/readahead.c
@@ -80,6 +80,8 @@ enum ra_class {
#include <linux/debugfs.h>
#include <linux/seq_file.h>
+#define DEBUG_READAHEAD_RADIXTREE
+
/* Read-ahead events to be accounted. */
enum ra_event {
RA_EVENT_CACHE_MISS, /* read cache misses */
@@ -1515,6 +1517,13 @@ static unsigned long query_page_cache_se
read_lock_irq(&mapping->tree_lock);
index = radix_tree_scan_hole_backward(&mapping->page_tree,
offset, ra_max);
+#ifdef DEBUG_READAHEAD_RADIXTREE
+ WARN_ON(index > offset);
+ if (index != offset)
+ WARN_ON(!__find_page(mapping, index + 1));
+ if (index && offset - index < ra_max)
+ WARN_ON(__find_page(mapping, index));
+#endif
read_unlock_irq(&mapping->tree_lock);
*remain = offset - index;
@@ -1550,6 +1559,11 @@ static unsigned long query_page_cache_se
struct radix_tree_node *node;
node = radix_tree_cache_lookup_node(&mapping->page_tree,
&cache, offset - count, 1);
+#ifdef DEBUG_READAHEAD_RADIXTREE
+ if (node != radix_tree_lookup_node(&mapping->page_tree,
+ offset - count, 1))
+ BUG();
+#endif
if (!node)
break;
}
@@ -1614,6 +1628,16 @@ static inline pgoff_t find_segtail(struc
cond_resched();
read_lock_irq(&mapping->tree_lock);
ra_index = radix_tree_scan_hole(&mapping->page_tree, index, max_scan);
+#ifdef DEBUG_READAHEAD_RADIXTREE
+ BUG_ON(!__find_page(mapping, index));
+ WARN_ON(ra_index < index);
+ if (ra_index != index && !__find_page(mapping, ra_index - 1))
+ printk(KERN_ERR "radix_tree_scan_hole(index=%lu ra_index=%lu "
+ "max_scan=%lu nrpages=%lu) fooled!\n",
+ index, ra_index, max_scan, mapping->nrpages);
+ if (ra_index != ~0UL && ra_index - index < max_scan)
+ WARN_ON(__find_page(mapping, ra_index));
+#endif
read_unlock_irq(&mapping->tree_lock);
if (ra_index <= index + max_scan)
--
next prev parent reply other threads:[~2006-03-19 2:35 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-03-19 2:34 [PATCH 00/23] Adaptive read-ahead V11 Wu Fengguang
2006-03-19 2:34 ` [PATCH 01/23] readahead: kconfig options Wu Fengguang
2006-03-19 2:34 ` [PATCH 02/23] radixtree: look-aside cache Wu Fengguang
2006-03-20 16:01 ` Christoph Lameter
2006-03-21 2:19 ` Wu Fengguang
2006-03-19 2:34 ` [PATCH 03/23] radixtree: hole scanning functions Wu Fengguang
2006-03-19 2:34 ` [PATCH 04/23] readahead: page flag PG_readahead Wu Fengguang
2006-03-19 2:34 ` [PATCH 05/23] readahead: refactor do_generic_mapping_read() Wu Fengguang
2006-03-19 2:34 ` [PATCH 06/23] readahead: refactor __do_page_cache_readahead() Wu Fengguang
2006-03-19 2:34 ` [PATCH 07/23] readahead: insert cond_resched() calls Wu Fengguang
2006-03-19 3:50 ` Lee Revell
2006-03-19 5:32 ` Wu Fengguang
2006-03-20 13:31 ` Wu Fengguang
2006-03-19 2:34 ` [PATCH 08/23] readahead: common macros Wu Fengguang
2006-03-19 2:34 ` [PATCH 09/23] readahead: events accounting Wu Fengguang
2006-03-19 2:34 ` [PATCH 10/23] readahead: support functions Wu Fengguang
2006-03-19 2:34 ` [PATCH 11/23] readahead: sysctl parameters Wu Fengguang
2006-03-19 2:34 ` [PATCH 12/23] readahead: min/max sizes Wu Fengguang
2006-03-19 2:34 ` [PATCH 13/23] readahead: page cache aging accounting Wu Fengguang
2006-03-19 2:34 ` [PATCH 14/23] readahead: state based method Wu Fengguang
2006-03-19 2:34 ` [PATCH 15/23] readahead: context " Wu Fengguang
2006-03-19 2:34 ` [PATCH 16/23] readahead: other methods Wu Fengguang
2006-03-19 2:34 ` [PATCH 17/23] readahead: call scheme Wu Fengguang
2006-03-19 2:34 ` [PATCH 18/23] readahead: laptop mode Wu Fengguang
2006-03-19 2:34 ` [PATCH 19/23] readahead: loop case Wu Fengguang
2006-03-19 2:34 ` [PATCH 20/23] readahead: nfsd case Wu Fengguang
2006-03-19 2:34 ` Wu Fengguang [this message]
2006-03-19 2:34 ` [PATCH 22/23] readahead: debug traces showing accessed file names Wu Fengguang
2006-03-19 2:34 ` [PATCH 23/23] readahead: debug traces showing read patterns Wu Fengguang
2006-03-19 3:10 ` [PATCH 00/23] Adaptive read-ahead V11 Jon Smirl
2006-03-19 3:47 ` Wu Fengguang
2006-03-19 4:10 ` Jon Smirl
2006-03-19 5:09 ` Wu Fengguang
2006-03-19 15:53 ` Jon Smirl
2006-03-20 13:54 ` Wu Fengguang
2006-03-27 21:38 ` Matt Heler
2006-03-28 3:44 ` Wu Fengguang
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