linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Lameter <cl@linux.com>
To: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>,
	Andi Kleen <andi@firstfloor.org>,
	tj@kernel.org, Metathronius Galabant <m.galabant@googlemail.com>,
	Matt Mackall <mpm@selenic.com>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Adrian Drzewiecki <z@drze.net>,
	linux-mm@kvack.org
Subject: [slub rfc1 11/12] slub: Remove kmem_cache_cpu dependency from acquire slab
Date: Fri, 02 Sep 2011 15:47:08 -0500	[thread overview]
Message-ID: <20110902204745.539298711@linux.com> (raw)
In-Reply-To: 20110902204657.105194589@linux.com

[-- Attachment #1: remove_kmem_cache_cpu_dependency_from_acquire_slab --]
[-- Type: text/plain, Size: 2363 bytes --]

Instead of putting the freepointer into the kmem_cache_cpu structure put it
into the page struct reusing the lru.next field.

Also convert the manual warning into a WARN_ON.

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

---
 mm/slub.c |   41 +++++++++++++++--------------------------
 1 file changed, 15 insertions(+), 26 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2011-09-02 10:12:25.981176437 -0500
+++ linux-2.6/mm/slub.c	2011-09-02 10:12:30.881176403 -0500
@@ -1569,37 +1569,25 @@ static inline int acquire_slab(struct km
 	 * The old freelist is the list of objects for the
 	 * per cpu allocation list.
 	 */
-	do {
-		freelist = page->freelist;
-		counters = page->counters;
-		new.counters = counters;
-		new.inuse = page->objects;
+	freelist = page->freelist;
+	counters = page->counters;
+	new.counters = counters;
+	new.inuse = page->objects;
 
-		VM_BUG_ON(new.frozen);
-		new.frozen = 1;
+	VM_BUG_ON(new.frozen);
+	new.frozen = 1;
 
-	} while (!__cmpxchg_double_slab(s, page,
+	if (!__cmpxchg_double_slab(s, page,
 			freelist, counters,
 			NULL, new.counters,
-			"lock and freeze"));
-
-	remove_partial(n, page);
+			"acquire_slab"))
 
-	if (freelist) {
-		/* Populate the per cpu freelist */
-		this_cpu_write(s->cpu_slab->freelist, freelist);
-		this_cpu_write(s->cpu_slab->page, page);
-		return 1;
-	} else {
-		/*
-		 * Slab page came from the wrong list. No object to allocate
-		 * from. Put it onto the correct list and continue partial
-		 * scan.
-		 */
-		printk(KERN_ERR "SLUB: %s : Page without available objects on"
-			" partial list\n", s->name);
 		return 0;
-	}
+
+	remove_partial(n, page);
+	WARN_ON(!freelist);
+	page->lru.next = freelist;
+	return 1;
 }
 
 /*
@@ -2133,7 +2121,8 @@ new_slab:
 	page = get_partial(s, gfpflags, node);
 	if (page) {
 		stat(s, ALLOC_FROM_PARTIAL);
-		freelist = c->freelist;
+		freelist = page->lru.next;
+		c->page  = page;
 		if (kmem_cache_debug(s))
 			goto debug;
 		goto load_freelist;

--
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:[~2011-09-02 20:47 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-02 20:46 [slub rfc1 00/12] slub: RFC lockless allocation paths V1 Christoph Lameter
2011-09-02 20:46 ` [slub rfc1 01/12] slub: free slabs without holding locks (V2) Christoph Lameter
2011-09-02 20:46 ` [slub rfc1 02/12] slub: Remove useless statements in __slab_alloc Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 03/12] slub: Get rid of the node field Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 04/12] slub: Separate out kmem_cache_cpu processing from deactivate_slab Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 05/12] slub: Extract get_freelist from __slab_alloc Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 06/12] slub: Use freelist instead of "object" in __slab_alloc Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 07/12] slub: pass page to node_match() instead of kmem_cache_cpu structure Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 08/12] slub: enable use of deactivate_slab with interrupts on Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 09/12] slub: Run deactivate_slab with interrupts enabled Christoph Lameter
2011-09-02 20:47 ` [slub rfc1 10/12] slub: Enable use of get_partial " Christoph Lameter
2011-09-02 20:47 ` Christoph Lameter [this message]
2011-09-02 20:47 ` [slub rfc1 12/12] slub: Drop page field from kmem_cache_cpu Christoph Lameter

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=20110902204745.539298711@linux.com \
    --to=cl@linux.com \
    --cc=andi@firstfloor.org \
    --cc=eric.dumazet@gmail.com \
    --cc=linux-mm@kvack.org \
    --cc=m.galabant@googlemail.com \
    --cc=mpm@selenic.com \
    --cc=penberg@cs.helsinki.fi \
    --cc=rientjes@google.com \
    --cc=tj@kernel.org \
    --cc=z@drze.net \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).