From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 700AD8D0080 for ; Wed, 17 Nov 2010 02:37:50 -0500 (EST) Received: from hpaq6.eem.corp.google.com (hpaq6.eem.corp.google.com [172.25.149.6]) by smtp-out.google.com with ESMTP id oAH7bkYn028753 for ; Tue, 16 Nov 2010 23:37:46 -0800 Received: from iwn3 (iwn3.prod.google.com [10.241.68.67]) by hpaq6.eem.corp.google.com with ESMTP id oAH7biPQ029140 for ; Tue, 16 Nov 2010 23:37:45 -0800 Received: by iwn3 with SMTP id 3so2005935iwn.26 for ; Tue, 16 Nov 2010 23:37:44 -0800 (PST) Date: Tue, 16 Nov 2010 23:37:39 -0800 (PST) From: David Rientjes Subject: Re: Propagating GFP_NOFS inside __vmalloc() In-Reply-To: Message-ID: References: <1289421759.11149.59.camel@oralap> <20101111120643.22dcda5b.akpm@linux-foundation.org> <1289512924.428.112.camel@oralap> <20101111142511.c98c3808.akpm@linux-foundation.org> <1289840500.13446.65.camel@oralap> <20101116141130.b20a8a8d.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andreas Dilger Cc: Andrew Morton , "Ricardo M. Correia" , linux-mm@kvack.org, Brian Behlendorf List-ID: On Wed, 17 Nov 2010, Andreas Dilger wrote: > >> - avoid doing anything other than GFP_KERNEL allocations for __vmalloc(): > >> the only current users are gfs2, ntfs, and ceph (the page allocator > >> __vmalloc() can be discounted since it's done at boot and GFP_ATOMIC > >> here has almost no chance of failing since the size is determined based > >> on what is available). > > > > ^^ this > > > > Using vmalloc anywhere is lame. > > I agree. What we really want is 1MB kmalloc() to work... :-/ > Order-8 allocations are already have a higher liklihood of succeeding because of memory compaction, which was explicitly targeted to aid in order-9 hugepage allocations. The problem is that it's useless for GFP_NOFS. I think removing gfp_t arguments from all of the public vmalloc interface will inevitably be where we go with this and everything will assume GFP_KERNEL | __GFP_HIGHMEM. If you _really_ need 1MB of physically contiguous memory, then you'll need to find a way to do it in a reclaimable context. If we actually can remove the dependency that gfs2, ntfs, and ceph have in the kernel.org kernel, then this support may be pulled out from under you; the worst-case scenario for Lustre is that you'll have to modify the callchains like I suggested in my original email to pass the gfp mask all the way down to the pte allocators if you can't find a way to do it under GFP_KERNEL. -- 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/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org