From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f174.google.com (mail-pf0-f174.google.com [209.85.192.174]) by kanga.kvack.org (Postfix) with ESMTP id EBF716B0005 for ; Tue, 29 Mar 2016 18:17:12 -0400 (EDT) Received: by mail-pf0-f174.google.com with SMTP id x3so25411410pfb.1 for ; Tue, 29 Mar 2016 15:17:12 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id d82si1247573pfj.52.2016.03.29.15.17.12 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 29 Mar 2016 15:17:12 -0700 (PDT) Date: Tue, 29 Mar 2016 15:17:10 -0700 From: Andrew Morton Subject: Re: [PATCH v4 3/8] mm: Add support for PUD-sized transparent hugepages Message-Id: <20160329151710.6a256611fd28637d5c40ac3c@linux-foundation.org> In-Reply-To: <1454242175-16870-4-git-send-email-matthew.r.wilcox@intel.com> References: <1454242175-16870-1-git-send-email-matthew.r.wilcox@intel.com> <1454242175-16870-4-git-send-email-matthew.r.wilcox@intel.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: Matthew Wilcox Cc: Matthew Wilcox , linux-mm@kvack.org, linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org On Sun, 31 Jan 2016 23:09:30 +1100 Matthew Wilcox wrote: > From: Matthew Wilcox > > The current transparent hugepage code only supports PMDs. This patch > adds support for transparent use of PUDs with DAX. It does not include > support for anonymous pages. > > Most of this patch simply parallels the work that was done for huge PMDs. > The only major difference is how the new ->pud_entry method in mm_walk > works. The ->pmd_entry method replaces the ->pte_entry method, whereas > the ->pud_entry method works along with either ->pmd_entry or ->pte_entry. > The pagewalk code takes care of locking the PUD before calling ->pud_walk, > so handlers do not need to worry whether the PUD is stable. Why is this patchset always so hard to compile :( > ... > > --- a/include/linux/pfn_t.h > +++ b/include/linux/pfn_t.h > @@ -82,6 +82,13 @@ static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot) > { > return pfn_pmd(pfn_t_to_pfn(pfn), pgprot); > } > + > +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD > +static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot) > +{ > + return pfn_pud(pfn_t_to_pfn(pfn), pgprot); > +} > +#endif > #endif > > #ifdef __HAVE_ARCH_PTE_DEVMAP > @@ -98,5 +105,6 @@ static inline bool pfn_t_devmap(pfn_t pfn) > } > pte_t pte_mkdevmap(pte_t pte); > pmd_t pmd_mkdevmap(pmd_t pmd); > +pud_t pud_mkdevmap(pud_t pud); arm allnoconfig: In file included from kernel/memremap.c:17: include/linux/pfn_t.h:107: error: 'pud_mkdevmap' declared as function returning an array because it expands to pgd_t pud_mkdevmap(pgd_t pud); and typedef unsigned long pgd_t[2]; Also the patch provides no implementation of pud_mkdevmap() so it's obviously going to break bisection. -- 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