From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B05CE77188 for ; Fri, 10 Jan 2025 06:25:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1195B6B0093; Fri, 10 Jan 2025 01:25:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C98C6B00AB; Fri, 10 Jan 2025 01:25:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ED3B96B00B0; Fri, 10 Jan 2025 01:25:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id CDC8B6B00AB for ; Fri, 10 Jan 2025 01:25:31 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 85B66C08AB for ; 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s=arc-20220608; d=hostedemail.com; t=1736490329; a=rsa-sha256; cv=none; b=D3LY0oPJEgVKVXXS4pqyXvf66XmBLYrNLtiVsg0CN2Toia9uGQ94ilew0V3cW82vCFlCbL 3gNOl9cbvaHtiL0oeVJQo5yew5NfhWjS9sw7JbGJmje+Nnpjr30m+gmyhLC1mdJJ6QRdn1 j4Qzj7ObHa5HW7haZFe7Z/lIn/gmhPc= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf10.hostedemail.com: domain of dev.jain@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=dev.jain@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 089291480; Thu, 9 Jan 2025 22:25:57 -0800 (PST) Received: from [10.162.42.21] (K4MQJ0H1H2.blr.arm.com [10.162.42.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F04213F673; Thu, 9 Jan 2025 22:25:16 -0800 (PST) Message-ID: Date: Fri, 10 Jan 2025 11:55:13 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 01/11] introduce khugepaged_collapse_single_pmd to collapse a single pmd To: Nico Pache , linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: ryan.roberts@arm.com, anshuman.khandual@arm.com, catalin.marinas@arm.com, cl@gentwo.org, vbabka@suse.cz, mhocko@suse.com, apopple@nvidia.com, dave.hansen@linux.intel.com, will@kernel.org, baohua@kernel.org, jack@suse.cz, srivatsa@csail.mit.edu, haowenchao22@gmail.com, hughd@google.com, aneesh.kumar@kernel.org, yang@os.amperecomputing.com, peterx@redhat.com, ioworker0@gmail.com, wangkefeng.wang@huawei.com, ziy@nvidia.com, jglisse@google.com, surenb@google.com, vishal.moola@gmail.com, zokeefe@google.com, zhengqi.arch@bytedance.com, jhubbard@nvidia.com, 21cnbao@gmail.com, willy@infradead.org, kirill.shutemov@linux.intel.com, david@redhat.com, aarcange@redhat.com, raquini@redhat.com, sunnanyong@huawei.com, usamaarif642@gmail.com, audra@redhat.com, akpm@linux-foundation.org References: <20250108233128.14484-1-npache@redhat.com> <20250108233128.14484-2-npache@redhat.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20250108233128.14484-2-npache@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: BCC99C0010 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 9qy78ygyh647axhie41b54zd7cr13a91 X-HE-Tag: 1736490329-746971 X-HE-Meta: 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 zFNCLJzq A1CnMloBc7fwulr/v8t+21TnDjgBIzZfx19tjDmWhK9hHWJscAcovyfxkyplQm6K4zIdm6M9kSFsLcdegsg62l9INW6Zi2hhp3S89NK4/oENQVEZ3Lequ+Xzm3Ba//l00wvFcwUTPPiadsSBiVuH4+s4Rlk7XEtvNxCn4yIvqTeVMHdUrjHiaf1nxitcb37u4YGNU/sA3+edhICJqJq2UnrVy/7sgJxB4N/hvPt9l1+XDnhi1YCdw2x6CEI1ZqdLUeCZX0ffZwZRqMJXaPFdPL3Y0+N98auNEKF8J7vAa3NSYACqcTXZoAUhHMbOZynlkIyp00B1FYNXtFqg6VBVVp4aPMQ== 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: List-Subscribe: List-Unsubscribe: On 09/01/25 5:01 am, Nico Pache wrote: > The khugepaged daemon and madvise_collapse have two different > implementations that do almost the thing. > > Create khugepaged_collapse_single_pmd to increase code > reuse and create a entry point for future khugepaged changes. > > Signed-off-by: Nico Pache > --- > mm/khugepaged.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 46 insertions(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 653dbb1ff05c..4d932839ff1d 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -2348,6 +2348,52 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr, > } > #endif > > +/* > + * Try to collapse a single PMD starting at a PMD aligned addr, and return > + * the results. > + */ > +static int khugepaged_collapse_single_pmd(unsigned long addr, struct mm_struct *mm, > + struct vm_area_struct *vma, bool *mmap_locked, > + struct collapse_control *cc) > +{ > + int result = SCAN_FAIL; > + unsigned long tva_flags = cc->is_khugepaged ? TVA_ENFORCE_SYSFS : 0; > + > + if (!*mmap_locked) { > + mmap_read_lock(mm); > + *mmap_locked = true; > + } > + > + if (thp_vma_allowable_order(vma, vma->vm_flags, > + tva_flags, PMD_ORDER)) { > + if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) { > + struct file *file = get_file(vma->vm_file); > + pgoff_t pgoff = linear_page_index(vma, addr); > + > + mmap_read_unlock(mm); > + *mmap_locked = false; > + result = hpage_collapse_scan_file(mm, addr, file, pgoff, > + cc); > + fput(file); > + if (result == SCAN_PTE_MAPPED_HUGEPAGE) { > + mmap_read_lock(mm); > + if (hpage_collapse_test_exit_or_disable(mm)) > + goto end; > + result = collapse_pte_mapped_thp(mm, addr, > + !cc->is_khugepaged); > + mmap_read_unlock(mm); > + } > + } else { > + result = hpage_collapse_scan_pmd(mm, vma, addr, > + mmap_locked, cc); > + } > + if (result == SCAN_SUCCEED || result == SCAN_PMD_MAPPED) > + ++khugepaged_pages_collapsed; > + } > +end: > + return result; > +} > + > static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result, > struct collapse_control *cc) > __releases(&khugepaged_mm_lock) I will suggest squashing this with patch 2 to avoid unused function warning when sequentially building patches.