From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id 6A05E6B0031 for ; Wed, 2 Oct 2013 01:47:41 -0400 (EDT) Received: by mail-pd0-f182.google.com with SMTP id r10so406525pdi.41 for ; Tue, 01 Oct 2013 22:47:41 -0700 (PDT) Received: by mail-pd0-f173.google.com with SMTP id p10so408881pdj.18 for ; Tue, 01 Oct 2013 22:47:38 -0700 (PDT) Date: Tue, 1 Oct 2013 22:47:36 -0700 (PDT) From: David Rientjes Subject: Re: [PATCH] mm: pagevec: cleanup: drop pvec->cold argument in all places In-Reply-To: <20130930150207.3661b5c146b6ecea84194547@linux-foundation.org> Message-ID: References: <1380357239-30102-1-git-send-email-bob.liu@oracle.com> <20130930150207.3661b5c146b6ecea84194547@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Bob Liu , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, viro@zeniv.linux.org.uk, mgorman@suse.de, hannes@cmpxchg.org, riel@redhat.com, minchan@kernel.org, Bob Liu On Mon, 30 Sep 2013, Andrew Morton wrote: > > Nobody uses the pvec->cold argument of pagevec and it's also unreasonable for > > pages in pagevec released as cold page, so drop the cold argument from pagevec. > > Is it unreasonable? I'd say it's unreasonable to assume that all pages > in all cases are likely to be cache-hot. Example: what if the pages > are being truncated and were found to be on the inactive LRU, > unreferenced? > > A useful exercise would be to go through all those pagevec_init() sites > and convince ourselves that the decision at each place was the correct > one. > Agreed, and the "cold" argument to release_pages() becomes a no-op if this patch is merged meaning that anything released through it will automatically go to the start of the pcp lists. If the pages aren't hot then this is exactly the opposite of what we wanted to do; the fact that the pvec length doesn't take into account the size of cpu cache can almost guarantee that everything isn't cache hot. -- 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/ . Don't email: email@kvack.org