From patchwork Wed Mar 4 10:28:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28Intel=29?= X-Patchwork-Id: 11419767 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2C51D17E0 for ; Wed, 4 Mar 2020 10:29:06 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E25D221741 for ; Wed, 4 Mar 2020 10:29:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=shipmail.org header.i=@shipmail.org header.b="aYDMzrpo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E25D221741 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shipmail.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 061876B000E; Wed, 4 Mar 2020 05:28:56 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id C42A06B0005; Wed, 4 Mar 2020 05:28:55 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E6E76B0003; Wed, 4 Mar 2020 05:28:55 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0190.hostedemail.com [216.40.44.190]) by kanga.kvack.org (Postfix) with ESMTP id 26B446B000A for ; Wed, 4 Mar 2020 05:28:55 -0500 (EST) Received: from smtpin01.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id A88278248047 for ; Wed, 4 Mar 2020 10:28:54 +0000 (UTC) X-FDA: 76557306588.01.fang98_6ac551658b15f X-Spam-Summary: 2,0,0,8b3b193b765fb8e8,d41d8cd98f00b204,thomas_os@shipmail.org,,RULES_HIT:41:152:355:379:541:800:960:968:973:988:989:1260:1261:1277:1311:1313:1314:1345:1359:1431:1437:1515:1516:1518:1535:1543:1593:1594:1676:1711:1730:1747:1777:1792:2393:2553:2559:2562:3138:3139:3140:3141:3142:3354:3865:3866:3867:3868:3870:3871:3872:3874:4117:4250:4321:5007:6119:6261:6653:6742:7576:7903:10004:10226:10400:11026:11232:11473:11658:11914:12043:12296:12297:12438:12517:12519:12555:12679:12895:12986:13161:13180:13229:13894:14181:14394:14659:14721:21080:21451:21627:21939:21990:30003:30054:30064:30090,0,RBL:213.80.101.70:@shipmail.org:.lbl8.mailshell.net-64.100.201.201 62.2.203.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fp,MSBL:0,DNSBL:none,Custom_rules:0:0:0,LFtime:24,LUA_SUMMARY:none X-HE-Tag: fang98_6ac551658b15f X-Filterd-Recvd-Size: 6174 Received: from ste-pvt-msa1.bahnhof.se (ste-pvt-msa1.bahnhof.se [213.80.101.70]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Wed, 4 Mar 2020 10:28:53 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by ste-pvt-msa1.bahnhof.se (Postfix) with ESMTP id 7ECCE3F888; Wed, 4 Mar 2020 11:28:52 +0100 (CET) Authentication-Results: ste-pvt-msa1.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=shipmail.org header.i=@shipmail.org header.b=aYDMzrpo; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at bahnhof.se X-Spam-Flag: NO X-Spam-Score: -2.099 X-Spam-Level: X-Spam-Status: No, score=-2.099 tagged_above=-999 required=6.31 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Received: from ste-pvt-msa1.bahnhof.se ([127.0.0.1]) by localhost (ste-pvt-msa1.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ovLp4pFr5_Wd; Wed, 4 Mar 2020 11:28:50 +0100 (CET) Received: from mail1.shipmail.org (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) (Authenticated sender: mb878879) by ste-pvt-msa1.bahnhof.se (Postfix) with ESMTPA id 5CC693F885; Wed, 4 Mar 2020 11:28:48 +0100 (CET) Received: from localhost.localdomain.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id 0E83136042F; Wed, 4 Mar 2020 11:28:48 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=shipmail.org; s=mail; t=1583317728; bh=eArF6ZjbQdomBzBVnzbUQcGFkrLPEvAM1NjLa5asgsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aYDMzrpoD0nNuFdNRG3boslnkJ3rFO1pNqTFdJzDcSDijQcx1cRVU0nVBP0ouv6pf qjDLfCcx2elKnNFohIkbfgdg91M67xEBCYHm0kFTqUbhgnHkt+nSBzysBEAeaviqL/ qsn1A4dTA6TfXugmDW4/HvLd2yNQwBqXVShRK0kY= From: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28VMware=29?= To: linux-mm@kvack.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: pv-drivers@vmware.com, linux-graphics-maintainer@vmware.com, Thomas Hellstrom , Andrew Morton , Michal Hocko , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Ralph Campbell , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , =?utf-8?q?Christian_?= =?utf-8?q?K=C3=B6nig?= , Dan Williams Subject: [PATCH v6 3/9] mm: Split huge pages on write-notify or COW Date: Wed, 4 Mar 2020 11:28:34 +0100 Message-Id: <20200304102840.2801-4-thomas_os@shipmail.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200304102840.2801-1-thomas_os@shipmail.org> References: <20200304102840.2801-1-thomas_os@shipmail.org> MIME-Version: 1.0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Thomas Hellstrom The functions wp_huge_pmd() and wp_huge_pud() currently relies on the huge_fault() callback to split huge page table entries if needed. However for module users that requires export of the split_huge_xxx() functionality which may be undesired. Instead split pre-existing huge page-table entries on VM_FAULT_FALLBACK return. We currently only do COW and write-notify on the PTE level, so if the huge_fault() handler returns VM_FAULT_FALLBACK on wp faults, split the huge pages and page-table entries. Also do this for huge PUDs if there is no huge_fault() handler and the vma is not anonymous, similar to how it's done for PMDs. Note that fs/dax.c still does the splitting in the huge_fault() handler, but as huge_fault() A follow-up patch can remove the dax.c split_huge_pmd() if needed. Cc: Andrew Morton Cc: Michal Hocko Cc: "Matthew Wilcox (Oracle)" Cc: "Kirill A. Shutemov" Cc: Ralph Campbell Cc: "Jérôme Glisse" Cc: "Christian König" Cc: Dan Williams Signed-off-by: Thomas Hellstrom Acked-by: Christian König --- mm/memory.c | 27 +++++++++++++++++++-------- 1 file changed, 19 insertions(+), 8 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 0bccc622e482..1e3fc1988790 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3932,11 +3932,14 @@ static inline vm_fault_t wp_huge_pmd(struct vm_fault *vmf, pmd_t orig_pmd) { if (vma_is_anonymous(vmf->vma)) return do_huge_pmd_wp_page(vmf, orig_pmd); - if (vmf->vma->vm_ops->huge_fault) - return vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD); + if (vmf->vma->vm_ops->huge_fault) { + vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PMD); - /* COW handled on pte level: split pmd */ - VM_BUG_ON_VMA(vmf->vma->vm_flags & VM_SHARED, vmf->vma); + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + } + + /* COW or write-notify handled on pte level: split pmd. */ __split_huge_pmd(vmf->vma, vmf->pmd, vmf->address, false, NULL); return VM_FAULT_FALLBACK; @@ -3949,12 +3952,20 @@ static inline bool vma_is_accessible(struct vm_area_struct *vma) static vm_fault_t create_huge_pud(struct vm_fault *vmf) { -#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \ + defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) /* No support for anonymous transparent PUD pages yet */ if (vma_is_anonymous(vmf->vma)) - return VM_FAULT_FALLBACK; - if (vmf->vma->vm_ops->huge_fault) - return vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD); + goto split; + if (vmf->vma->vm_ops->huge_fault) { + vm_fault_t ret = vmf->vma->vm_ops->huge_fault(vmf, PE_SIZE_PUD); + + if (!(ret & VM_FAULT_FALLBACK)) + return ret; + } +split: + /* COW or write-notify not handled on PUD level: split pud.*/ + __split_huge_pud(vmf->vma, vmf->pud, vmf->address); #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ return VM_FAULT_FALLBACK; }