From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 25 Jan 2005 01:04:57 +0000 From: Matthew Wilcox Subject: Re: [PATCH] Remove special case in kmem_getpages() Message-ID: <20050125010457.GR31455@parcelfarce.linux.theplanet.co.uk> References: <20050124165412.GL31455@parcelfarce.linux.theplanet.co.uk> <41F5999B.3060608@didntduck.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41F5999B.3060608@didntduck.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Brian Gerst Cc: Matthew Wilcox , Andrew Morton , linux-mm@kvack.org, manfred@colorfullife.com, linux-kernel@vger.kernel.org, dhowells@redhat.com List-ID: On Mon, Jan 24, 2005 at 07:58:03PM -0500, Brian Gerst wrote: > Matthew Wilcox wrote: > >__get_free_pages() calls alloc_pages, finds the page_address() and > >throws away the struct page *. Slab then calls virt_to_page to get it > >back again. Much more efficient for slab to call alloc_pages itself, > >as well as making the NUMA and non-NUMA cases more similarr to each other. > > Here is a better patch: I disagree. This disables the alloc_pages_current() optimisation. I considered this option and rejected it. > Remove the special case of nodeid == -1. Instead, use numa_node_id() > when calling cache_grow(). > > Signed-off-by: Brian Gerst > diff -urN linux-2.6.11-rc2-bk/mm/slab.c linux/mm/slab.c > --- linux-2.6.11-rc2-bk/mm/slab.c 2005-01-22 01:58:25.000000000 -0500 > +++ linux/mm/slab.c 2005-01-24 15:35:08.000000000 -0500 > @@ -893,17 +893,11 @@ > int i; > > flags |= cachep->gfpflags; > - if (likely(nodeid == -1)) { > - addr = (void*)__get_free_pages(flags, cachep->gfporder); > - if (!addr) > - return NULL; > - page = virt_to_page(addr); > - } else { > - page = alloc_pages_node(nodeid, flags, cachep->gfporder); > - if (!page) > - return NULL; > - addr = page_address(page); > - } > + > + page = alloc_pages_node(nodeid, flags, cachep->gfporder); > + if (!page) > + return NULL; > + addr = page_address(page); > > i = (1 << cachep->gfporder); > if (cachep->flags & SLAB_RECLAIM_ACCOUNT) > @@ -2065,7 +2059,7 @@ > > if (unlikely(!ac->avail)) { > int x; > - x = cache_grow(cachep, flags, -1); > + x = cache_grow(cachep, flags, numa_node_id()); > > // cache_grow can reenable interrupts, then ac could change. > ac = ac_data(cachep); -- "Next the statesmen will invent cheap lies, putting the blame upon the nation that is attacked, and every man will be glad of those conscience-soothing falsities, and will diligently study them, and refuse to examine any refutations of them; and thus he will by and by convince himself that the war is just, and will thank God for the better sleep he enjoys after this process of grotesque self-deception." -- Mark Twain -- 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: aart@kvack.org