From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 3CF2E6B0007 for ; Tue, 9 Oct 2018 08:36:40 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id z12-v6so985305pfl.17 for ; Tue, 09 Oct 2018 05:36:40 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 37-v6si19334435pgu.460.2018.10.09.05.36.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 09 Oct 2018 05:36:39 -0700 (PDT) Date: Tue, 9 Oct 2018 14:36:35 +0200 From: Michal Hocko Subject: Re: [PATCH 2/2] mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask Message-ID: <20181009123635.GO8528@dhcp22.suse.cz> References: <20180925120326.24392-1-mhocko@kernel.org> <20180925120326.24392-3-mhocko@kernel.org> <20180926133039.y7o5x4nafovxzh2s@kshutemo-mobl1> 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: David Rientjes Cc: "Kirill A. Shutemov" , Andrew Morton , Mel Gorman , Vlastimil Babka , Andrea Argangeli , Zi Yan , Stefan Priebe - Profihost AG , linux-mm@kvack.org, LKML On Thu 04-10-18 13:17:52, David Rientjes wrote: > On Wed, 26 Sep 2018, Kirill A. Shutemov wrote: > > > On Tue, Sep 25, 2018 at 02:03:26PM +0200, Michal Hocko wrote: > > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > > > index c3bc7e9c9a2a..c0bcede31930 100644 > > > --- a/mm/huge_memory.c > > > +++ b/mm/huge_memory.c > > > @@ -629,21 +629,40 @@ static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, > > > * available > > > * never: never stall for any thp allocation > > > */ > > > -static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma) > > > +static inline gfp_t alloc_hugepage_direct_gfpmask(struct vm_area_struct *vma, unsigned long addr) > > > { > > > const bool vma_madvised = !!(vma->vm_flags & VM_HUGEPAGE); > > > + gfp_t this_node = 0; > > > + > > > +#ifdef CONFIG_NUMA > > > + struct mempolicy *pol; > > > + /* > > > + * __GFP_THISNODE is used only when __GFP_DIRECT_RECLAIM is not > > > + * specified, to express a general desire to stay on the current > > > + * node for optimistic allocation attempts. If the defrag mode > > > + * and/or madvise hint requires the direct reclaim then we prefer > > > + * to fallback to other node rather than node reclaim because that > > > + * can lead to excessive reclaim even though there is free memory > > > + * on other nodes. We expect that NUMA preferences are specified > > > + * by memory policies. > > > + */ > > > + pol = get_vma_policy(vma, addr); > > > + if (pol->mode != MPOL_BIND) > > > + this_node = __GFP_THISNODE; > > > + mpol_cond_put(pol); > > > +#endif > > > > I'm not very good with NUMA policies. Could you explain in more details how > > the code above is equivalent to the code below? > > > > It breaks mbind() because new_page() is now using numa_node_id() to > allocate migration targets for instead of using the mempolicy. I'm not > sure that this patch was tested for mbind(). I am sorry but I do not follow, could you be more specific please? MPOL_BIND should never get __GFP_THISNODE. What am I missing? -- Michal Hocko SUSE Labs