linux-kernel - [PATCH v2] zsmalloc: consider ZS_ALMOST

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: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 10 Jul 2015 14:31:59 +0900
From:	Minchan Kim <minchan@...nel.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Sergey Senozhatsky <sergey.senozhatsky@...il.com>,
	Nitin Gupta <ngupta@...are.org>, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, Minchan Kim <minchan.kim@....com>
Subject: [PATCH v2] zsmalloc: consider ZS_ALMOST_FULL as migrate source

From: Minchan Kim <minchan.kim@....com>

There is no reason to prevent select ZS_ALMOST_FULL as migration
source if we cannot find source from ZS_ALMOST_EMPTY.

With this patch, zs_can_compact will return more exact result.

* From v1
  * remove unnecessary found variable - Sergey

Signed-off-by: Minchan Kim <minchan.kim@....com>
---
 mm/zsmalloc.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 8c78bcb..9012645 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -1686,11 +1686,17 @@ static enum fullness_group putback_zspage(struct zs_pool *pool,
 
 static struct page *isolate_source_page(struct size_class *class)
 {
-	struct page *page;
+	int i;
+	struct page *page = NULL;
+
+	for (i = ZS_ALMOST_EMPTY; i >= ZS_ALMOST_FULL; i--) {
+		page = class->fullness_list[i];
+		if (!page)
+			continue;
 
-	page = class->fullness_list[ZS_ALMOST_EMPTY];
-	if (page)
-		remove_zspage(page, class, ZS_ALMOST_EMPTY);
+		remove_zspage(page, class, i);
+		break;
+	}
 
 	return page;
 }
@@ -1706,9 +1712,6 @@ static unsigned long zs_can_compact(struct size_class *class)
 {
 	unsigned long obj_wasted;
 
-	if (!zs_stat_get(class, CLASS_ALMOST_EMPTY))
-		return 0;
-
 	obj_wasted = zs_stat_get(class, OBJ_ALLOCATED) -
 		zs_stat_get(class, OBJ_USED);
 
-- 
1.7.9.5

--
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/