From patchwork Wed Jan 20 17:36:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12033039 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54379C433DB for ; Wed, 20 Jan 2021 17:36:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D0B1B23122 for ; Wed, 20 Jan 2021 17:36:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D0B1B23122 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 438A36B000C; Wed, 20 Jan 2021 12:36:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3EE846B000D; Wed, 20 Jan 2021 12:36:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2B2106B000E; Wed, 20 Jan 2021 12:36:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0139.hostedemail.com [216.40.44.139]) by kanga.kvack.org (Postfix) with ESMTP id 161F76B000C for ; Wed, 20 Jan 2021 12:36:38 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CC24B8249980 for ; Wed, 20 Jan 2021 17:36:37 +0000 (UTC) X-FDA: 77726858034.23.fog02_0c02cfe2755c Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id ABDFC37608 for ; Wed, 20 Jan 2021 17:36:37 +0000 (UTC) X-HE-Tag: fog02_0c02cfe2755c X-Filterd-Recvd-Size: 8084 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Wed, 20 Jan 2021 17:36:36 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id B73242070A; Wed, 20 Jan 2021 17:36:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611164196; bh=0pn7bgAeZDKGcdVrLp6LkRvBAhpX3ko/rgDGtAX8D/g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XBbI+cW5nTMlH6QSQRgVkTEBVvtv4u6GsHqzTtYhEpsjvPu60/sLBlrQCMfYIazZs ILwZD3avrfsn1ktk8J8uTn16xfq+EldSoErBTdmFA6gZdhou9syARHucXjG46ukvGC VrOFDd2VLvwjPUBdSYLJCW8zf7PStqVJfDUvw4dIyYroO1WS3bipJBgDk7F+wCaCTp PHHqhJ6uXPkwudGNTJeU6wdrn0rCYO/eI2DsYPMNMaiIozIXlzBLqStuYywvriJqNb TdyBjarkLYF9OYr97HocAB1WEodd7YYP8ajk+b3UKrdjvDBv/EUOhzW+pmRph0QKIk ir/TzMXaRrRrw== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Will Deacon , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Linus Torvalds , Vinayak Menon , Hugh Dickins , Nick Desaulniers , kernel-team@android.com Subject: [PATCH v4 5/8] mm: Pass 'address' to map to do_set_pte() and drop FAULT_FLAG_PREFAULT Date: Wed, 20 Jan 2021 17:36:09 +0000 Message-Id: <20210120173612.20913-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210120173612.20913-1-will@kernel.org> References: <20210120173612.20913-1-will@kernel.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: Rather than modifying the 'address' field of the 'struct vm_fault' passed to do_set_pte(), leave that to identify the real faulting address and pass in the virtual address to be mapped by the new pte as a separate argument. This makes FAULT_FLAG_PREFAULT redundant, as a prefault entry can be identified simply by comparing the new address parameter with the faulting address, so remove the redundant flag at the same time. Cc: Kirill A. Shutemov Cc: Linus Torvalds Signed-off-by: Will Deacon --- include/linux/mm.h | 7 ++----- mm/filemap.c | 21 +++++++-------------- mm/memory.c | 10 +++++----- 3 files changed, 14 insertions(+), 24 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index b4a5cb9bff7d..e0f056753bef 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -434,7 +434,6 @@ extern pgprot_t protection_map[16]; * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. - * @FAULT_FLAG_PREFAULT: Fault was a prefault. * * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify * whether we would allow page faults to retry by specifying these two @@ -465,7 +464,6 @@ extern pgprot_t protection_map[16]; #define FAULT_FLAG_REMOTE 0x80 #define FAULT_FLAG_INSTRUCTION 0x100 #define FAULT_FLAG_INTERRUPTIBLE 0x200 -#define FAULT_FLAG_PREFAULT 0x400 /* * The default fault flags that should be used by most of the @@ -503,8 +501,7 @@ static inline bool fault_flag_allow_retry_first(unsigned int flags) { FAULT_FLAG_USER, "USER" }, \ { FAULT_FLAG_REMOTE, "REMOTE" }, \ { FAULT_FLAG_INSTRUCTION, "INSTRUCTION" }, \ - { FAULT_FLAG_INTERRUPTIBLE, "INTERRUPTIBLE" }, \ - { FAULT_FLAG_PREFAULT, "PREFAULT" } + { FAULT_FLAG_INTERRUPTIBLE, "INTERRUPTIBLE" } /* * vm_fault is filled by the pagefault handler and passed to the vma's @@ -995,7 +992,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma) } vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page); -void do_set_pte(struct vm_fault *vmf, struct page *page); +void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr); vm_fault_t finish_fault(struct vm_fault *vmf); vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf); diff --git a/mm/filemap.c b/mm/filemap.c index a6dc97906c8e..fb7a8d9b5603 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3018,8 +3018,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, struct file *file = vma->vm_file; struct address_space *mapping = file->f_mapping; pgoff_t last_pgoff = start_pgoff; - unsigned long address = vmf->address; - unsigned long flags = vmf->flags; + unsigned long addr; XA_STATE(xas, &mapping->i_pages, start_pgoff); struct page *head, *page; unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss); @@ -3035,8 +3034,8 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, goto out; } - vmf->address = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT); - vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, vmf->address, &vmf->ptl); + addr = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT); + vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, addr, &vmf->ptl); do { page = find_subpage(head, xas.xa_index); if (PageHWPoison(page)) @@ -3045,7 +3044,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, if (mmap_miss > 0) mmap_miss--; - vmf->address += (xas.xa_index - last_pgoff) << PAGE_SHIFT; + addr += (xas.xa_index - last_pgoff) << PAGE_SHIFT; vmf->pte += xas.xa_index - last_pgoff; last_pgoff = xas.xa_index; @@ -3053,16 +3052,12 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, goto unlock; /* We're about to handle the fault */ - if (vmf->address == address) { - vmf->flags &= ~FAULT_FLAG_PREFAULT; + if (vmf->address == addr) ret = VM_FAULT_NOPAGE; - } else { - vmf->flags |= FAULT_FLAG_PREFAULT; - } - do_set_pte(vmf, page); + do_set_pte(vmf, page, addr); /* no need to invalidate: a not-present page won't be cached */ - update_mmu_cache(vma, vmf->address, vmf->pte); + update_mmu_cache(vma, addr, vmf->pte); unlock_page(head); continue; unlock: @@ -3072,8 +3067,6 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, pte_unmap_unlock(vmf->pte, vmf->ptl); out: rcu_read_unlock(); - vmf->flags = flags; - vmf->address = address; WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss); return ret; } diff --git a/mm/memory.c b/mm/memory.c index f0e7c589ca9d..7b1307873325 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3733,11 +3733,11 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) } #endif -void do_set_pte(struct vm_fault *vmf, struct page *page) +void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr) { struct vm_area_struct *vma = vmf->vma; bool write = vmf->flags & FAULT_FLAG_WRITE; - bool prefault = vmf->flags & FAULT_FLAG_PREFAULT; + bool prefault = vmf->address != addr; pte_t entry; flush_icache_page(vma, page); @@ -3753,13 +3753,13 @@ void do_set_pte(struct vm_fault *vmf, struct page *page) /* copy-on-write page */ if (write && !(vma->vm_flags & VM_SHARED)) { inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); - page_add_new_anon_rmap(page, vma, vmf->address, false); + page_add_new_anon_rmap(page, vma, addr, false); lru_cache_add_inactive_or_unevictable(page, vma); } else { inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page)); page_add_file_rmap(page, false); } - set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry); + set_pte_at(vma->vm_mm, addr, vmf->pte, entry); } /** @@ -3819,7 +3819,7 @@ vm_fault_t finish_fault(struct vm_fault *vmf) ret = 0; /* Re-check under ptl */ if (likely(pte_none(*vmf->pte))) - do_set_pte(vmf, page); + do_set_pte(vmf, page, vmf->address); else ret = VM_FAULT_NOPAGE;