From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f70.google.com (mail-it0-f70.google.com [209.85.214.70]) by kanga.kvack.org (Postfix) with ESMTP id 3E3426B026A for ; Thu, 26 Jan 2017 06:04:19 -0500 (EST) Received: by mail-it0-f70.google.com with SMTP id s10so40030445itb.7 for ; Thu, 26 Jan 2017 03:04:19 -0800 (PST) Received: from www62.your-server.de (www62.your-server.de. [213.133.104.62]) by mx.google.com with ESMTPS id k64si1589810iof.5.2017.01.26.03.04.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Jan 2017 03:04:18 -0800 (PST) Message-ID: <5889D7AD.5030103@iogearbox.net> Date: Thu, 26 Jan 2017 12:04:13 +0100 From: Daniel Borkmann MIME-Version: 1.0 Subject: Re: [PATCH 0/6 v3] kvmalloc References: <588907AA.1020704@iogearbox.net> <20170126074354.GB8456@dhcp22.suse.cz> <5889C331.7020101@iogearbox.net> <20170126100802.GF6590@dhcp22.suse.cz> <20170126103216.GG6590@dhcp22.suse.cz> In-Reply-To: <20170126103216.GG6590@dhcp22.suse.cz> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Alexei Starovoitov , Andrew Morton , Vlastimil Babka , Mel Gorman , Johannes Weiner , linux-mm , LKML , "netdev@vger.kernel.org" , marcelo.leitner@gmail.com On 01/26/2017 11:32 AM, Michal Hocko wrote: > On Thu 26-01-17 11:08:02, Michal Hocko wrote: >> On Thu 26-01-17 10:36:49, Daniel Borkmann wrote: >>> On 01/26/2017 08:43 AM, Michal Hocko wrote: >>>> On Wed 25-01-17 21:16:42, Daniel Borkmann wrote: >> [...] >>>>> I assume that kvzalloc() is still the same from [1], right? If so, then >>>>> it would unfortunately (partially) reintroduce the issue that was fixed. >>>>> If you look above at flags, they're also passed to __vmalloc() to not >>>>> trigger OOM in these situations I've experienced. >>>> >>>> Pushing __GFP_NORETRY to __vmalloc doesn't have the effect you might >>>> think it would. It can still trigger the OOM killer becauset the flags >>>> are no propagated all the way down to all allocations requests (e.g. >>>> page tables). This is the same reason why GFP_NOFS is not supported in >>>> vmalloc. >>> >>> Ok, good to know, is that somewhere clearly documented (like for the >>> case with kmalloc())? >> >> I am afraid that we really suck on this front. I will add something. > > So I have folded the following to the patch 1. It is in line with > kvmalloc and hopefully at least tell more than the current code. > --- > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index d89034a393f2..6c1aa2c68887 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -1741,6 +1741,13 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, > * Allocate enough pages to cover @size from the page level > * allocator with @gfp_mask flags. Map them into contiguous > * kernel virtual space, using a pagetable protection of @prot. > + * > + * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_REPEAT > + * and __GFP_NOFAIL are not supported We could probably also mention that __GFP_ZERO in @gfp_mask is supported, though. > + * Any use of gfp flags outside of GFP_KERNEL should be consulted > + * with mm people. Just a question: should that read 'GFP_KERNEL | __GFP_HIGHMEM' as that is what vmalloc() resp. vzalloc() and others pass as flags? > + * > */ Sounds good otherwise, thanks Michal! > static void *__vmalloc_node(unsigned long size, unsigned long align, > gfp_t gfp_mask, pgprot_t prot, -- 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