From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f197.google.com (mail-pf0-f197.google.com [209.85.192.197]) by kanga.kvack.org (Postfix) with ESMTP id 8CF1C6B0038 for ; Fri, 12 May 2017 17:35:07 -0400 (EDT) Received: by mail-pf0-f197.google.com with SMTP id y65so53311430pff.13 for ; Fri, 12 May 2017 14:35:07 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id q8si4322572pgc.167.2017.05.12.14.35.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 12 May 2017 14:35:06 -0700 (PDT) Date: Fri, 12 May 2017 14:35:03 -0700 From: Andrew Morton Subject: Re: [PATCH V2] mm/madvise: Enable (soft|hard) offline of HugeTLB pages at PGD level Message-Id: <20170512143503.81e0de2ae3d88a53168c601a@linux-foundation.org> In-Reply-To: <20170426035731.6924-1-khandual@linux.vnet.ibm.com> References: <20170426035731.6924-1-khandual@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Anshuman Khandual Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, n-horiguchi@ah.jp.nec.com, aneesh.kumar@linux.vnet.ibm.com On Wed, 26 Apr 2017 09:27:31 +0530 Anshuman Khandual wrote: > Though migrating gigantic HugeTLB pages does not sound much like real > world use case, they can be affected by memory errors. Hence migration > at the PGD level HugeTLB pages should be supported just to enable soft > and hard offline use cases. > > While allocating the new gigantic HugeTLB page, it should not matter > whether new page comes from the same node or not. There would be very > few gigantic pages on the system afterall, we should not be bothered > about node locality when trying to save a big page from crashing. > > This introduces a new HugeTLB allocator called alloc_huge_page_nonid() > which will scan over all online nodes on the system and allocate a > single HugeTLB page. > > ... > > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -1669,6 +1669,23 @@ struct page *__alloc_buddy_huge_page_with_mpol(struct hstate *h, > return __alloc_buddy_huge_page(h, vma, addr, NUMA_NO_NODE); > } > > +struct page *alloc_huge_page_nonid(struct hstate *h) > +{ > + struct page *page = NULL; > + int nid = 0; > + > + spin_lock(&hugetlb_lock); > + if (h->free_huge_pages - h->resv_huge_pages > 0) { > + for_each_online_node(nid) { > + page = dequeue_huge_page_node(h, nid); > + if (page) > + break; > + } > + } > + spin_unlock(&hugetlb_lock); > + return page; > +} > + > /* > * This allocation function is useful in the context where vma is irrelevant. > * E.g. soft-offlining uses this function because it only cares physical > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index fe64d7729a8e..d4f5710cf3f7 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1481,11 +1481,15 @@ EXPORT_SYMBOL(unpoison_memory); > static struct page *new_page(struct page *p, unsigned long private, int **x) > { > int nid = page_to_nid(p); > - if (PageHuge(p)) > + if (PageHuge(p)) { > + if (hstate_is_gigantic(page_hstate(compound_head(p)))) > + return alloc_huge_page_nonid(page_hstate(compound_head(p))); > + > return alloc_huge_page_node(page_hstate(compound_head(p)), > nid); > - else > + } else { > return __alloc_pages_node(nid, GFP_HIGHUSER_MOVABLE, 0); > + } > } Rather than adding alloc_huge_page_nonid(), would it be neater to teach alloc_huge_page_node() (actually dequeue_huge_page_node()) to understand nid==NUMA_NO_NODE? -- 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