linux-kernel - [PATCH 4/7] zram/xvmalloc: free bit block insertion optimization

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

Message-ID: <20110126172508.GF8446@linux.vnet.ibm.com>
Date:	Wed, 26 Jan 2011 11:25:08 -0600
From:	Robert Jennings <rcj@...ux.vnet.ibm.com>
To:	Nitin Gupta <ngupta@...are.org>
Cc:	Greg Kroah-Hartman <gregkh@...e.de>,
	Robert Jennings <rcj@...ux.vnet.ibm.com>,
	Pekka Enberg <penberg@...helsinki.fi>,
	devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Subject: [PATCH 4/7] zram/xvmalloc: free bit block insertion optimization

There is no need to set the bits in the first- and second-level indices
to indicate a free page when we know that a free page existed at this
level.

Signed-off-by: Robert Jennings <rcj@...ux.vnet.ibm.com>
---
 drivers/staging/zram/xvmalloc.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/zram/xvmalloc.c b/drivers/staging/zram/xvmalloc.c
index a507f95..b3622f1 100644
--- a/drivers/staging/zram/xvmalloc.c
+++ b/drivers/staging/zram/xvmalloc.c
@@ -205,6 +205,8 @@ static void insert_block(struct xv_pool *pool, struct page *page, u32 offset,
 		nextblock->link.prev_page = page;
 		nextblock->link.prev_offset = offset;
 		put_ptr_atomic(nextblock, KM_USER1);
+		/* If there was a next page then the free bits are set. */
+		return;
 	}
 
 	__set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]);
-- 
1.6.0.2

--
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/