From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by kanga.kvack.org (Postfix) with ESMTP id 2D69F6B0038 for ; Mon, 11 May 2015 18:40:18 -0400 (EDT) Received: by pabsx10 with SMTP id sx10so120763906pab.3 for ; Mon, 11 May 2015 15:40:17 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id a3si19567167pbu.253.2015.05.11.15.40.17 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 11 May 2015 15:40:17 -0700 (PDT) Date: Mon, 11 May 2015 15:40:15 -0700 From: Andrew Morton Subject: Re: [PATCH V3] mm/thp: Split out pmd collpase flush into a separate functions Message-Id: <20150511154015.956459466f1ca96fc84723b7@linux-foundation.org> In-Reply-To: <1431326370-24247-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1431326370-24247-1-git-send-email-aneesh.kumar@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: "Aneesh Kumar K.V" Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, kirill.shutemov@linux.intel.com, aarcange@redhat.com, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, 11 May 2015 12:09:30 +0530 "Aneesh Kumar K.V" wrote: > Architectures like ppc64 [1] need to do special things while clearing > pmd before a collapse. For them this operation is largely different > from a normal hugepage pte clear. Hence add a separate function > to clear pmd before collapse. After this patch pmdp_* functions > operate only on hugepage pte, and not on regular pmd_t values > pointing to page table. > > [1] ppc64 needs to invalidate all the normal page pte mappings we > already have inserted in the hardware hash page table. But before > doing that we need to make sure there are no parallel hash page > table insert going on. So we need to do a kick_all_cpus_sync() > before flushing the older hash table entries. By moving this to > a separate function we capture these details and mention how it > is different from a hugepage pte clear. > > This patch is a cleanup and only does code movement for clarity. > There should not be any change in functionality. > > ... > > +#ifndef pmd_collapse_flush > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +static inline pmd_t pmd_collapse_flush(struct vm_area_struct *vma, > + unsigned long address, > + pmd_t *pmdp) > +{ > + return pmdp_clear_flush(vma, address, pmdp); > +} > +#else > +static inline pmd_t pmd_collapse_flush(struct vm_area_struct *vma, > + unsigned long address, > + pmd_t *pmdp) > +{ > + BUILD_BUG(); > + return __pmd(0); > +} > +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ You want #define pmd_collapse_flush pmd_collapse_flush here, just in case a later header file performs the same test. > +#endif > + -- 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