From patchwork Thu Jan 14 17:59:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Will Deacon X-Patchwork-Id: 12020473 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 557B7C433DB for ; Thu, 14 Jan 2021 18:01:03 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0118623A34 for ; Thu, 14 Jan 2021 18:01:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0118623A34 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 6AE1D8D00FC; Thu, 14 Jan 2021 13:01:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 65D658D00F0; Thu, 14 Jan 2021 13:01:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 529368D00FC; Thu, 14 Jan 2021 13:01:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0089.hostedemail.com [216.40.44.89]) by kanga.kvack.org (Postfix) with ESMTP id 331A78D00F0 for ; Thu, 14 Jan 2021 13:01:00 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 027AD2491 for ; Thu, 14 Jan 2021 18:01:00 +0000 (UTC) X-FDA: 77705146680.10.chin35_38150e027528 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id BFB1F16A4BA for ; Thu, 14 Jan 2021 18:00:59 +0000 (UTC) X-HE-Tag: chin35_38150e027528 X-Filterd-Recvd-Size: 8123 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Thu, 14 Jan 2021 18:00:58 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 00F0423B79; Thu, 14 Jan 2021 18:00:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1610647258; bh=CLWZyv41YTti7pvhWRzPDEtPLCfiI6EClMAI6/Ld1fg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SJMrbnzspRpeSRI7dZBjnZ0vGXNbgelPRQ1K5SowwdgLjb6Vuif4UOT3zVV3RR7ab cgTKsAdOBlJEfCGucCtw5XWH44gUYwkELgXj/F7tnFepyUncIsA6tx3br7+arGAeLG KSCv7OEbFWA3JdVu0ypf5NI8RT1iuZCjwaSVMXFDMo3LvRxTIiul+l/c1HH3uA2Bq5 bU4PNuJclHUe+1+gAbpMGDmqj4SppPRNKSb9HELTjtAyiu3n6rm6kmA3iZe43UyRYP DZim5okUpwJtJwgkzmOVd4QwG7O8R2KUBg/BHl7H9HT7YPVzrbieEQ0NaW1/Bf6nkP gz9u72h/vB4QQ== 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 , kernel-team@android.com Subject: [RFC PATCH 5/8] mm: Pass 'address' to map to do_set_pte() and drop FAULT_FLAG_PREFAULT Date: Thu, 14 Jan 2021 17:59:31 +0000 Message-Id: <20210114175934.13070-6-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210114175934.13070-1-will@kernel.org> References: <20210114175934.13070-1-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_info' 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 | 22 +++++++--------------- mm/memory.c | 10 +++++----- 3 files changed, 14 insertions(+), 25 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 15e8dd77b8ff..c24dd17b32c5 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 @@ -997,7 +994,7 @@ 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 c192e103843f..46ca16bf1372 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->info.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); @@ -3035,9 +3034,8 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, goto out; } - vmf->info.address = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT); - vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, - vmf->info.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)) @@ -3046,7 +3044,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, if (mmap_miss > 0) mmap_miss--; - vmf->info.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; @@ -3054,16 +3052,12 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, goto unlock; /* We're about to handle the fault */ - if (vmf->info.address == address) { - vmf->flags &= ~FAULT_FLAG_PREFAULT; + if (vmf->info.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->info.address, vmf->pte); + update_mmu_cache(vma, addr, vmf->pte); unlock_page(head); continue; unlock: @@ -3073,8 +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->info.address = address; WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss); return ret; } diff --git a/mm/memory.c b/mm/memory.c index ffb7598046fc..f19184542974 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3741,11 +3741,11 @@ 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->info.vma; bool write = vmf->flags & FAULT_FLAG_WRITE; - bool prefault = vmf->flags & FAULT_FLAG_PREFAULT; + bool prefault = vmf->info.address != addr; pte_t entry; flush_icache_page(vma, page); @@ -3761,13 +3761,13 @@ 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->info.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->info.address, vmf->pte, entry); + set_pte_at(vma->vm_mm, addr, vmf->pte, entry); } /** @@ -3827,7 +3827,7 @@ 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->info.address); else ret = VM_FAULT_NOPAGE;