lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri,  5 Jun 2015 21:03:52 +0900
From:	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
To:	Andrew Morton <akpm@...ux-foundation.org>,
	Minchan Kim <minchan@...nel.org>
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	Sergey Senozhatsky <sergey.senozhatsky.work@...il.com>,
	Sergey Senozhatsky <sergey.senozhatsky@...il.com>
Subject: [RFC][PATCHv2 2/8] zsmalloc: partial page ordering within a fullness_list

We want to see more ZS_FULL pages and less ZS_ALMOST_{FULL, EMPTY}
pages. Put a page with higher ->inuse count first within its
->fullness_list, which will give us better chances to fill up this
page with new objects (find_get_zspage() return ->fullness_list head
for new object allocation), so some zspages will become
ZS_ALMOST_FULL/ZS_FULL quicker.

It performs a trivial and cheap ->inuse compare which does not slow
down zsmalloc, and in the worst case it keeps the list pages not in
any particular order, just like we do it now.

A more expensive solution could sort fullness_list by ->inuse count.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@...il.com>
---
 mm/zsmalloc.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index ce3310c..cd37bda 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -658,8 +658,16 @@ static void insert_zspage(struct page *page, struct size_class *class,
 		return;
 
 	head = &class->fullness_list[fullness];
-	if (*head)
-		list_add_tail(&page->lru, &(*head)->lru);
+	if (*head) {
+		/*
+		 * We want to see more ZS_FULL pages and less almost
+		 * empty/full. Put pages with higher ->inuse first.
+		 */
+		if (page->inuse < (*head)->inuse)
+			list_add_tail(&page->lru, &(*head)->lru);
+		else
+			list_add(&page->lru, &(*head)->lru);
+	}
 
 	*head = page;
 	zs_stat_inc(class, fullness == ZS_ALMOST_EMPTY ?
-- 
2.4.2.387.gf86f31a

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists