From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dukat.scot.redhat.com (sct@dukat.scot.redhat.com [195.89.149.246]) by kvack.org (8.8.7/8.8.7) with ESMTP id RAA17513 for ; Tue, 6 Apr 1999 17:11:38 -0400 From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <14090.30842.367364.230774@dukat.scot.redhat.com> Date: Tue, 6 Apr 1999 22:11:22 +0100 (BST) Subject: Re: [patch] arca-vm-2.2.5 In-Reply-To: References: Sender: owner-linux-mm@kvack.org To: Chuck Lever Cc: Andrea Arcangeli , "Stephen C. Tweedie" , linux-kernel@vger.rutgers.edu, linux-mm@kvack.org List-ID: Hi, On Tue, 6 Apr 1999 16:47:23 -0400 (EDT), Chuck Lever said: >> but I was just assuming that the offset is always page-aligned. >> I could write a simulation to check the hash function... > i didn't realize that the "offset" argument would always be page-aligned. > but still, why does it help to add the unshifted "offset"? doesn't seem > like there's any new information in that. It is always aligned for the page cache (hence mixing in the lower bits to the hash function shouldn't change anything), but the swap cache uses the lower bits extensively, concentrating the swap cache into just a few hash buckets unless we make this change. --Stephen -- To unsubscribe, send a message with 'unsubscribe linux-mm my@address' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/