From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by kanga.kvack.org (Postfix) with ESMTP id 2A7ED6B0032 for ; Mon, 15 Dec 2014 21:37:59 -0500 (EST) Received: by mail-pa0-f43.google.com with SMTP id kx10so13156927pab.30 for ; Mon, 15 Dec 2014 18:37:58 -0800 (PST) Received: from lgemrelse7q.lge.com (LGEMRELSE7Q.lge.com. [156.147.1.151]) by mx.google.com with ESMTP id qd7si5554289pdb.124.2014.12.15.18.37.55 for ; Mon, 15 Dec 2014 18:37:57 -0800 (PST) Date: Tue, 16 Dec 2014 11:42:10 +0900 From: Joonsoo Kim Subject: Re: [PATCH 3/7] slub: Do not use c->page on free Message-ID: <20141216024210.GB23270@js1304-P5Q-DELUXE> References: <20141210163017.092096069@linux.com> <20141210163033.717707217@linux.com> <20141215080338.GE4898@js1304-P5Q-DELUXE> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: akpm@linuxfoundation.org, rostedt@goodmis.org, linux-kernel@vger.kernel.org, Thomas Gleixner , linux-mm@kvack.org, penberg@kernel.org, Jesper Dangaard Brouer On Mon, Dec 15, 2014 at 08:16:00AM -0600, Christoph Lameter wrote: > On Mon, 15 Dec 2014, Joonsoo Kim wrote: > > > > +static bool same_slab_page(struct kmem_cache *s, struct page *page, void *p) > > > +{ > > > + long d = p - page->address; > > > + > > > + return d > 0 && d < (1 << MAX_ORDER) && d < (compound_order(page) << PAGE_SHIFT); > > > +} > > > + > > > > Somtimes, compound_order() induces one more cacheline access, because > > compound_order() access second struct page in order to get order. Is there > > any way to remove this? > > I already have code there to avoid the access if its within a MAX_ORDER > page. We could probably go for a smaller setting there. PAGE_COSTLY_ORDER? That is the solution to avoid compound_order() call when slab of object isn't matched with per cpu slab. What I'm asking is whether there is a way to avoid compound_order() call when slab of object is matched with per cpu slab or not. Thanks. -- 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