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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 567F2C433F5 for ; Tue, 10 May 2022 21:10:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230433AbiEJVKh (ORCPT ); Tue, 10 May 2022 17:10:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231302AbiEJVKe (ORCPT ); Tue, 10 May 2022 17:10:34 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2E5A294481 for ; Tue, 10 May 2022 14:10:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9580AB81FE8 for ; Tue, 10 May 2022 21:10:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 490FCC385CD; Tue, 10 May 2022 21:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1652217029; bh=sIqAU3Xd4QO4A1BIDYb2sb7sm99shc7661L3t2VbPIc=; h=Date:To:From:Subject:From; b=WDAajvZAk/Ou0HtXzTlwR94IGiyxspTQyBwXpLas+yHtqE22XWg0r6GAzD3jdCq2X 5+PwHfPDVZCz4No7A6WVgAMLGQoUgr3ihOttLfO0BFX2VeUYE++X+3cYeCP8MZaXj+ tAdDHMT+tua5C0eeZ+7xi/fKbCTL2ls4Y9boD7BA= Date: Tue, 10 May 2022 14:10:28 -0700 To: mm-commits@vger.kernel.org, ziy@nvidia.com, willy@infradead.org, vbabka@suse.cz, tytso@mit.edu, songliubraving@fb.com, song@kernel.org, riel@surriel.com, linmiaohe@huawei.com, kirill.shutemov@linux.intel.com, shy828301@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-khugepaged-make-khugepaged_enter-void-function.patch added to mm-unstable branch Message-Id: <20220510211029.490FCC385CD@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm: khugepaged: make khugepaged_enter() void function has been added to the -mm mm-unstable branch. Its filename is mm-khugepaged-make-khugepaged_enter-void-function.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-khugepaged-make-khugepaged_enter-void-function.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Yang Shi Subject: mm: khugepaged: make khugepaged_enter() void function The most callers of khugepaged_enter() don't care about the return value. Only dup_mmap(), anonymous THP page fault and MADV_HUGEPAGE handle the error by returning -ENOMEM. Actually it is not harmful for them to ignore the error case either. It also sounds overkilling to fail fork() and page fault early due to khugepaged_enter() error, and MADV_HUGEPAGE does set VM_HUGEPAGE flag regardless of the error. Link: https://lkml.kernel.org/r/20220510203222.24246-6-shy828301@gmail.com Signed-off-by: Yang Shi Acked-by: Song Liu Acked-by: Vlastmil Babka Cc: Kirill A. Shutemov Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Rik van Riel Cc: Song Liu Cc: Theodore Ts'o Cc: Zi Yan Signed-off-by: Andrew Morton --- include/linux/khugepaged.h | 30 ++++++++++++------------------ kernel/fork.c | 4 +--- mm/huge_memory.c | 4 ++-- mm/khugepaged.c | 18 +++++++----------- 4 files changed, 22 insertions(+), 34 deletions(-) --- a/include/linux/khugepaged.h~mm-khugepaged-make-khugepaged_enter-void-function +++ a/include/linux/khugepaged.h @@ -12,10 +12,10 @@ extern struct attribute_group khugepaged extern int khugepaged_init(void); extern void khugepaged_destroy(void); extern int start_stop_khugepaged(void); -extern int __khugepaged_enter(struct mm_struct *mm); +extern void __khugepaged_enter(struct mm_struct *mm); extern void __khugepaged_exit(struct mm_struct *mm); -extern int khugepaged_enter_vma_merge(struct vm_area_struct *vma, - unsigned long vm_flags); +extern void khugepaged_enter_vma_merge(struct vm_area_struct *vma, + unsigned long vm_flags); extern void khugepaged_min_free_kbytes_update(void); #ifdef CONFIG_SHMEM extern void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr); @@ -40,11 +40,10 @@ static inline void collapse_pte_mapped_t (transparent_hugepage_flags & \ (1<flags)) - return __khugepaged_enter(mm); - return 0; + __khugepaged_enter(mm); } static inline void khugepaged_exit(struct mm_struct *mm) @@ -53,7 +52,7 @@ static inline void khugepaged_exit(struc __khugepaged_exit(mm); } -static inline int khugepaged_enter(struct vm_area_struct *vma, +static inline void khugepaged_enter(struct vm_area_struct *vma, unsigned long vm_flags) { if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags)) @@ -62,27 +61,22 @@ static inline int khugepaged_enter(struc (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) && !(vm_flags & VM_NOHUGEPAGE) && !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) - if (__khugepaged_enter(vma->vm_mm)) - return -ENOMEM; - return 0; + __khugepaged_enter(vma->vm_mm); } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ -static inline int khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm) +static inline void khugepaged_fork(struct mm_struct *mm, struct mm_struct *oldmm) { - return 0; } static inline void khugepaged_exit(struct mm_struct *mm) { } -static inline int khugepaged_enter(struct vm_area_struct *vma, - unsigned long vm_flags) +static inline void khugepaged_enter(struct vm_area_struct *vma, + unsigned long vm_flags) { - return 0; } -static inline int khugepaged_enter_vma_merge(struct vm_area_struct *vma, - unsigned long vm_flags) +static inline void khugepaged_enter_vma_merge(struct vm_area_struct *vma, + unsigned long vm_flags) { - return 0; } static inline void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) --- a/kernel/fork.c~mm-khugepaged-make-khugepaged_enter-void-function +++ a/kernel/fork.c @@ -608,9 +608,7 @@ static __latent_entropy int dup_mmap(str retval = ksm_fork(mm, oldmm); if (retval) goto out; - retval = khugepaged_fork(mm, oldmm); - if (retval) - goto out; + khugepaged_fork(mm, oldmm); retval = mas_expected_entries(&mas, oldmm->map_count); if (retval) --- a/mm/huge_memory.c~mm-khugepaged-make-khugepaged_enter-void-function +++ a/mm/huge_memory.c @@ -726,8 +726,8 @@ vm_fault_t do_huge_pmd_anonymous_page(st return VM_FAULT_FALLBACK; if (unlikely(anon_vma_prepare(vma))) return VM_FAULT_OOM; - if (unlikely(khugepaged_enter(vma, vma->vm_flags))) - return VM_FAULT_OOM; + khugepaged_enter(vma, vma->vm_flags); + if (!(vmf->flags & FAULT_FLAG_WRITE) && !mm_forbids_zeropage(vma->vm_mm) && transparent_hugepage_use_zero_page()) { --- a/mm/khugepaged.c~mm-khugepaged-make-khugepaged_enter-void-function +++ a/mm/khugepaged.c @@ -365,8 +365,7 @@ int hugepage_madvise(struct vm_area_stru * register it here without waiting a page fault that * may not happen any time soon. */ - if (khugepaged_enter_vma_merge(vma, *vm_flags)) - return -ENOMEM; + khugepaged_enter_vma_merge(vma, *vm_flags); break; case MADV_NOHUGEPAGE: *vm_flags &= ~VM_HUGEPAGE; @@ -475,20 +474,20 @@ static bool hugepage_vma_check(struct vm return true; } -int __khugepaged_enter(struct mm_struct *mm) +void __khugepaged_enter(struct mm_struct *mm) { struct mm_slot *mm_slot; int wakeup; mm_slot = alloc_mm_slot(); if (!mm_slot) - return -ENOMEM; + return; /* __khugepaged_exit() must not run from under us */ VM_BUG_ON_MM(khugepaged_test_exit(mm), mm); if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) { free_mm_slot(mm_slot); - return 0; + return; } spin_lock(&khugepaged_mm_lock); @@ -504,11 +503,9 @@ int __khugepaged_enter(struct mm_struct mmgrab(mm); if (wakeup) wake_up_interruptible(&khugepaged_wait); - - return 0; } -int khugepaged_enter_vma_merge(struct vm_area_struct *vma, +void khugepaged_enter_vma_merge(struct vm_area_struct *vma, unsigned long vm_flags) { unsigned long hstart, hend; @@ -519,13 +516,12 @@ int khugepaged_enter_vma_merge(struct vm * file-private shmem THP is not supported. */ if (!hugepage_vma_check(vma, vm_flags)) - return 0; + return; hstart = (vma->vm_start + ~HPAGE_PMD_MASK) & HPAGE_PMD_MASK; hend = vma->vm_end & HPAGE_PMD_MASK; if (hstart < hend) - return khugepaged_enter(vma, vm_flags); - return 0; + khugepaged_enter(vma, vm_flags); } void __khugepaged_exit(struct mm_struct *mm) _ Patches currently in -mm which might be from shy828301@gmail.com are sched-coredumph-clarify-the-use-of-mmf_vm_hugepage.patch mm-khugepaged-remove-redundant-check-for-vm_no_khugepaged.patch mm-khugepaged-skip-dax-vma.patch mm-thp-only-regular-file-could-be-thp-eligible.patch mm-khugepaged-make-khugepaged_enter-void-function.patch mm-khugepaged-make-hugepage_vma_check-non-static.patch mm-khugepaged-introduce-khugepaged_enter_vma-helper.patch mm-mmap-register-suitable-readonly-file-vmas-for-khugepaged.patch