From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: Re: Should PAGE_CACHE_SIZE be discarded? Date: Wed, 14 Nov 2007 15:59:39 +0000 Message-ID: <22558.1195055979@redhat.com> References: <20071114152345.GB20973@wotan.suse.de> <17161.1195048613@redhat.com> Cc: dhowells@redhat.com, torvalds@osdl.org, linux-arch@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Nick Piggin Return-path: Received: from mx1.redhat.com ([66.187.233.31]:60610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754156AbXKNP7o (ORCPT ); Wed, 14 Nov 2007 10:59:44 -0500 In-Reply-To: <20071114152345.GB20973@wotan.suse.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Nick Piggin wrote: > Christoph Lameter has patches exactly to make PAGE_CACHE_SIZE larger than > PAGE_SIZE, and they seem to work without much effort. I happen to hate the > patches ;) but that doesn't change the fact that PAGE_CACHE_SIZE is > relatively useful and it is not at all an ill-defined concept. Where, please? mm kernels? > Basically, anything that goes in the page cache is in units of > PAGE_CACHE_SIZE, and nothing else. For filesystems it should be pretty > easy... That depends on what the coverage of struct page is. I don't actually know whether this is PAGE_SIZE or PAGE_CACHE_SIZE; I assumed it to be the former, but from what you've said, I'm not actually sure. David