From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id CF807199BC for ; Wed, 10 Sep 2025 04:06:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757477192; cv=none; b=fzd3hRAidQWWQGP58NwlUvaB6h5V8gEY7l/4tQIelSl5dnNGnSzY83yZHZhEHVzXuRx9lp21l+xE/9Cyz/fQVa1h+pdTIVar3AlDX3FhMZNADvZ/6VUOtE3J1yXaHRer+v404WSyjnfjm6vdxN+fSn+CElifeckA00G26NRhPnQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757477192; c=relaxed/simple; bh=U0JXJ/7n51Kts9btcObJG0iKMTWOA2Btxw1//eHNdvM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=p975+/GqjFg60QQ40+ZDDGw0sRZXjd+heO1mWaCiJQPuVLRH4oHXnZNd1czkkg7kMExbQBY0ed773YjMz+NncuzkAG6npirx6SKl4QgbvZqA++Qs8fyOL18Mbd0JWcxoJHvZJ4VEBTNb1S1yzAd1rTYyRUp5+lWo5yJHsTrSOhM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=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 CD8191596; Tue, 9 Sep 2025 21:06:21 -0700 (PDT) Received: from [10.163.41.55] (unknown [10.163.41.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8BDC43F66E; Tue, 9 Sep 2025 21:06:19 -0700 (PDT) Message-ID: <8f0cdb97-ea43-4142-993a-17d47762602c@arm.com> Date: Wed, 10 Sep 2025 09:36:14 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/2] mm: Drop all references of writable and SCAN_PAGE_RO To: Dev Jain , akpm@linux-foundation.org, david@redhat.com, kas@kernel.org, willy@infradead.org, hughd@google.com Cc: ziy@nvidia.com, baolin.wang@linux.alibaba.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, baohua@kernel.org, richard.weiyang@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20250908075028.38431-1-dev.jain@arm.com> <20250908075028.38431-3-dev.jain@arm.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250908075028.38431-3-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 08/09/25 1:20 PM, Dev Jain wrote: > Now that all actionable outcomes from checking pte_write() are gone, > drop the related references. > > Acked-by: David Hildenbrand > Acked-by: Zi Yan > Reviewed-by: Kiryl Shutsemau > Reviewed-by: Lorenzo Stoakes > Reviewed-by: Baolin Wang > Signed-off-by: Dev Jain Reviewed-by: Anshuman Khandual > --- > include/trace/events/huge_memory.h | 19 ++++++------------- > mm/khugepaged.c | 14 +++----------- > 2 files changed, 9 insertions(+), 24 deletions(-) > > diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h > index 2305df6cb485..dd94d14a2427 100644 > --- a/include/trace/events/huge_memory.h > +++ b/include/trace/events/huge_memory.h > @@ -19,7 +19,6 @@ > EM( SCAN_PTE_NON_PRESENT, "pte_non_present") \ > EM( SCAN_PTE_UFFD_WP, "pte_uffd_wp") \ > EM( SCAN_PTE_MAPPED_HUGEPAGE, "pte_mapped_hugepage") \ > - EM( SCAN_PAGE_RO, "no_writable_page") \ > EM( SCAN_LACK_REFERENCED_PAGE, "lack_referenced_page") \ > EM( SCAN_PAGE_NULL, "page_null") \ > EM( SCAN_SCAN_ABORT, "scan_aborted") \ > @@ -55,15 +54,14 @@ SCAN_STATUS > > TRACE_EVENT(mm_khugepaged_scan_pmd, > > - TP_PROTO(struct mm_struct *mm, struct folio *folio, bool writable, > + TP_PROTO(struct mm_struct *mm, struct folio *folio, > int referenced, int none_or_zero, int status, int unmapped), > > - TP_ARGS(mm, folio, writable, referenced, none_or_zero, status, unmapped), > + TP_ARGS(mm, folio, referenced, none_or_zero, status, unmapped), > > TP_STRUCT__entry( > __field(struct mm_struct *, mm) > __field(unsigned long, pfn) > - __field(bool, writable) > __field(int, referenced) > __field(int, none_or_zero) > __field(int, status) > @@ -73,17 +71,15 @@ TRACE_EVENT(mm_khugepaged_scan_pmd, > TP_fast_assign( > __entry->mm = mm; > __entry->pfn = folio ? folio_pfn(folio) : -1; > - __entry->writable = writable; > __entry->referenced = referenced; > __entry->none_or_zero = none_or_zero; > __entry->status = status; > __entry->unmapped = unmapped; > ), > > - TP_printk("mm=%p, scan_pfn=0x%lx, writable=%d, referenced=%d, none_or_zero=%d, status=%s, unmapped=%d", > + TP_printk("mm=%p, scan_pfn=0x%lx, referenced=%d, none_or_zero=%d, status=%s, unmapped=%d", > __entry->mm, > __entry->pfn, > - __entry->writable, > __entry->referenced, > __entry->none_or_zero, > __print_symbolic(__entry->status, SCAN_STATUS), > @@ -117,15 +113,14 @@ TRACE_EVENT(mm_collapse_huge_page, > TRACE_EVENT(mm_collapse_huge_page_isolate, > > TP_PROTO(struct folio *folio, int none_or_zero, > - int referenced, bool writable, int status), > + int referenced, int status), > > - TP_ARGS(folio, none_or_zero, referenced, writable, status), > + TP_ARGS(folio, none_or_zero, referenced, status), > > TP_STRUCT__entry( > __field(unsigned long, pfn) > __field(int, none_or_zero) > __field(int, referenced) > - __field(bool, writable) > __field(int, status) > ), > > @@ -133,15 +128,13 @@ TRACE_EVENT(mm_collapse_huge_page_isolate, > __entry->pfn = folio ? folio_pfn(folio) : -1; > __entry->none_or_zero = none_or_zero; > __entry->referenced = referenced; > - __entry->writable = writable; > __entry->status = status; > ), > > - TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, writable=%d, status=%s", > + TP_printk("scan_pfn=0x%lx, none_or_zero=%d, referenced=%d, status=%s", > __entry->pfn, > __entry->none_or_zero, > __entry->referenced, > - __entry->writable, > __print_symbolic(__entry->status, SCAN_STATUS)) > ); > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index a0f1df2a7ae6..af5f5c80fe4e 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -39,7 +39,6 @@ enum scan_result { > SCAN_PTE_NON_PRESENT, > SCAN_PTE_UFFD_WP, > SCAN_PTE_MAPPED_HUGEPAGE, > - SCAN_PAGE_RO, > SCAN_LACK_REFERENCED_PAGE, > SCAN_PAGE_NULL, > SCAN_SCAN_ABORT, > @@ -557,7 +556,6 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > struct folio *folio = NULL; > pte_t *_pte; > int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0; > - bool writable = false; > > for (_pte = pte; _pte < pte + HPAGE_PMD_NR; > _pte++, address += PAGE_SIZE) { > @@ -671,9 +669,6 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > folio_test_referenced(folio) || mmu_notifier_test_young(vma->vm_mm, > address))) > referenced++; > - > - if (pte_write(pteval)) > - writable = true; > } > > if (unlikely(cc->is_khugepaged && !referenced)) { > @@ -681,13 +676,13 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, > } else { > result = SCAN_SUCCEED; > trace_mm_collapse_huge_page_isolate(folio, none_or_zero, > - referenced, writable, result); > + referenced, result); > return result; > } > out: > release_pte_pages(pte, _pte, compound_pagelist); > trace_mm_collapse_huge_page_isolate(folio, none_or_zero, > - referenced, writable, result); > + referenced, result); > return result; > } > > @@ -1280,7 +1275,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, > unsigned long _address; > spinlock_t *ptl; > int node = NUMA_NO_NODE, unmapped = 0; > - bool writable = false; > > VM_BUG_ON(address & ~HPAGE_PMD_MASK); > > @@ -1344,8 +1338,6 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, > result = SCAN_PTE_UFFD_WP; > goto out_unmap; > } > - if (pte_write(pteval)) > - writable = true; > > page = vm_normal_page(vma, _address, pteval); > if (unlikely(!page) || unlikely(is_zone_device_page(page))) { > @@ -1435,7 +1427,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm, > *mmap_locked = false; > } > out: > - trace_mm_khugepaged_scan_pmd(mm, folio, writable, referenced, > + trace_mm_khugepaged_scan_pmd(mm, folio, referenced, > none_or_zero, result, unmapped); > return result; > }