All of lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Lameter <cl@linux.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: linux-mm@kvack.org, David Rientjes <rientjes@google.com>
Subject: [Slub cleanup6 2/5] slub: get_map() function to establish map of free objects in a slab
Date: Fri, 15 Apr 2011 14:48:13 -0500	[thread overview]
Message-ID: <20110415194830.839125394@linux.com> (raw)
In-Reply-To: 20110415194811.810587216@linux.com

[-- Attachment #1: slub_slowpath_get_map --]
[-- Type: text/plain, Size: 2992 bytes --]

The bit map of free objects in a slab page is determined in various functions
if debugging is enabled.

Provide a common function for that purpose.

Signed-off-by: Christoph Lameter <cl@linux.com>

---
 mm/slub.c |   34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-03-30 14:09:27.000000000 -0500
+++ linux-2.6/mm/slub.c	2011-03-30 14:30:24.000000000 -0500
@@ -271,10 +271,6 @@ static inline void set_freepointer(struc
 	for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\
 			__p += (__s)->size)
 
-/* Scan freelist */
-#define for_each_free_object(__p, __s, __free) \
-	for (__p = (__free); __p; __p = get_freepointer((__s), __p))
-
 /* Determine object index from a given position */
 static inline int slab_index(void *p, struct kmem_cache *s, void *addr)
 {
@@ -330,6 +326,21 @@ static inline int oo_objects(struct kmem
 	return x.x & OO_MASK;
 }
 
+/*
+ * Determine a map of object in use on a page.
+ *
+ * Slab lock or node listlock must be held to guarantee that the page does
+ * not vanish from under us.
+ */
+static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map)
+{
+	void *p;
+	void *addr = page_address(page);
+
+	for (p = page->freelist; p; p = get_freepointer(s, p))
+		set_bit(slab_index(p, s, addr), map);
+}
+
 #ifdef CONFIG_SLUB_DEBUG
 /*
  * Debug settings:
@@ -2673,9 +2684,8 @@ static void list_slab_objects(struct kme
 		return;
 	slab_err(s, page, "%s", text);
 	slab_lock(page);
-	for_each_free_object(p, s, page->freelist)
-		set_bit(slab_index(p, s, addr), map);
 
+	get_map(s, page, map);
 	for_each_object(p, s, addr, page->objects) {
 
 		if (!test_bit(slab_index(p, s, addr), map)) {
@@ -3610,10 +3620,11 @@ static int validate_slab(struct kmem_cac
 	/* Now we know that a valid freelist exists */
 	bitmap_zero(map, page->objects);
 
-	for_each_free_object(p, s, page->freelist) {
-		set_bit(slab_index(p, s, addr), map);
-		if (!check_object(s, page, p, SLUB_RED_INACTIVE))
-			return 0;
+	get_map(s, page, map);
+	for_each_object(p, s, addr, page->objects) {
+		if (test_bit(slab_index(p, s, addr), map))
+			if (!check_object(s, page, p, SLUB_RED_INACTIVE))
+				return 0;
 	}
 
 	for_each_object(p, s, addr, page->objects)
@@ -3821,8 +3832,7 @@ static void process_slab(struct loc_trac
 	void *p;
 
 	bitmap_zero(map, page->objects);
-	for_each_free_object(p, s, page->freelist)
-		set_bit(slab_index(p, s, addr), map);
+	get_map(s, page, map);
 
 	for_each_object(p, s, addr, page->objects)
 		if (!test_bit(slab_index(p, s, addr), map))

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  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@kvack.org"> email@kvack.org </a>

  parent reply	other threads:[~2011-04-15 19:48 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-15 19:48 [Slub cleanup6 0/5] SLUB: Cleanups V6 Christoph Lameter
2011-04-15 19:48 ` [Slub cleanup6 1/5] slub: Use NUMA_NO_NODE in get_partial Christoph Lameter
2011-05-11 20:03   ` David Rientjes
2011-04-15 19:48 ` Christoph Lameter [this message]
2011-05-11 20:03   ` [Slub cleanup6 2/5] slub: get_map() function to establish map of free objects in a slab David Rientjes
2011-05-12 16:41     ` Christoph Lameter
2011-05-12 20:01       ` David Rientjes
2011-04-15 19:48 ` [Slub cleanup6 3/5] slub: Eliminate repeated use of c->page through a new page variable Christoph Lameter
2011-05-11 20:03   ` David Rientjes
2011-04-15 19:48 ` [Slub cleanup6 4/5] slub: Move node determination out of hotpath Christoph Lameter
2011-05-11 20:03   ` David Rientjes
2011-05-12 16:44     ` Christoph Lameter
2011-05-12 20:10       ` [patch] slub: avoid label inside conditional David Rientjes
2011-05-13 14:49         ` Christoph Lameter
2011-04-15 19:48 ` [Slub cleanup6 5/5] slub: Move debug handlign in __slab_free Christoph Lameter
2011-05-11 20:03   ` David Rientjes
2011-04-17 11:05 ` [Slub cleanup6 0/5] SLUB: Cleanups V6 Pekka Enberg

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110415194830.839125394@linux.com \
    --to=cl@linux.com \
    --cc=linux-mm@kvack.org \
    --cc=penberg@cs.helsinki.fi \
    --cc=rientjes@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.