From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77249146004 for ; Mon, 13 May 2024 05:08:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715576927; cv=none; b=b8/kOFoYfT2IFp6A7hgpTNZJj0Zcu+FUiHRC7cK8Ry6hD/F+UYfsBYPtV1VfgQ2tLgitsvH04/2/tVhbf93Yya0woEbDdS9BPdT8QLZqQ8ecC1OAZxLlFM1w7dRPd4r7GGD9sOyws9d00FOJKt/HjLPBY/vy+tKENkSEqs2bCKw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715576927; c=relaxed/simple; bh=nMSF1IFNK+xtK1MkmmMs2/4yvCnaAux+3CiGthjHebQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=dVMSu8brZvRu/DDMLoPL9kLetTN5K7Xdo3lw7cufgY/k5LJLhAV/oOjwGiwly5eOMV5rh6ybRpLZ/s5xQFDHxjXrlgxqR9dfUkEpBC9OxEtZ1C4NuD1L+IeKhY78uEmlsrLnd5yU5yGw2wnTjto78agVP9i+cBO42Z4wm9d5FNo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=YMUTmWTT; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="YMUTmWTT" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1715576916; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=/wPvXkyuXgii0bLFUI24fcIW75QnUckPu3WAKMN0v0o=; b=YMUTmWTT1UYtaBphNlJ83Z0UnGWSGCE0+ov7/10Ik9Tn5PxQBQiq09cWTGntFbo7toUqx+uSk9njFnAV92U2ZCcpalXPqOuFa+HkGkBiQQsjxtUpSGl+qYSAnGuAR10TfvgVupdkEozq1XSn7VYknhjkBZUl8+aLLfdalaWC6pg= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R271e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033022160150;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0W6HFTB5_1715576913; Received: from localhost(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0W6HFTB5_1715576913) by smtp.aliyun-inc.com; Mon, 13 May 2024 13:08:34 +0800 From: Baolin Wang To: akpm@linux-foundation.org, hughd@google.com Cc: willy@infradead.org, david@redhat.com, ioworker0@gmail.com, wangkefeng.wang@huawei.com, ying.huang@intel.com, 21cnbao@gmail.com, ryan.roberts@arm.com, shy828301@gmail.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 1/7] mm: memory: extend finish_fault() to support large folio Date: Mon, 13 May 2024 13:08:11 +0800 Message-Id: <131bcf31a07fade15a012ed5cdf7156d42a4c2fa.1715571279.git.baolin.wang@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add large folio mapping establishment support for finish_fault() as a preparation, to support multi-size THP allocation of anonymous shmem pages in the following patches. Signed-off-by: Baolin Wang --- mm/memory.c | 58 ++++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 48 insertions(+), 10 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index eea6e4984eae..f5ffe012556c 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4747,9 +4747,12 @@ vm_fault_t finish_fault(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct page *page; + struct folio *folio; vm_fault_t ret; bool is_cow = (vmf->flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED); + int type, nr_pages, i; + unsigned long addr = vmf->address; /* Did we COW the page? */ if (is_cow) @@ -4780,24 +4783,59 @@ vm_fault_t finish_fault(struct vm_fault *vmf) return VM_FAULT_OOM; } + folio = page_folio(page); + nr_pages = folio_nr_pages(folio); + + /* + * Using per-page fault to maintain the uffd semantics, and same + * approach also applies to non-anonymous-shmem faults to avoid + * inflating the RSS of the process. + */ + if (!vma_is_anon_shmem(vma) || unlikely(userfaultfd_armed(vma))) { + nr_pages = 1; + } else if (nr_pages > 1) { + pgoff_t idx = folio_page_idx(folio, page); + /* The page offset of vmf->address within the VMA. */ + pgoff_t vma_off = vmf->pgoff - vmf->vma->vm_pgoff; + + /* + * Fallback to per-page fault in case the folio size in page + * cache beyond the VMA limits. + */ + if (unlikely(vma_off < idx || + vma_off + (nr_pages - idx) > vma_pages(vma))) { + nr_pages = 1; + } else { + /* Now we can set mappings for the whole large folio. */ + addr = vmf->address - idx * PAGE_SIZE; + page = &folio->page; + } + } + vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, - vmf->address, &vmf->ptl); + addr, &vmf->ptl); if (!vmf->pte) return VM_FAULT_NOPAGE; /* Re-check under ptl */ - if (likely(!vmf_pte_changed(vmf))) { - struct folio *folio = page_folio(page); - int type = is_cow ? MM_ANONPAGES : mm_counter_file(folio); - - set_pte_range(vmf, folio, page, 1, vmf->address); - add_mm_counter(vma->vm_mm, type, 1); - ret = 0; - } else { - update_mmu_tlb(vma, vmf->address, vmf->pte); + if (nr_pages == 1 && unlikely(vmf_pte_changed(vmf))) { + update_mmu_tlb(vma, addr, vmf->pte); + ret = VM_FAULT_NOPAGE; + goto unlock; + } else if (nr_pages > 1 && !pte_range_none(vmf->pte, nr_pages)) { + for (i = 0; i < nr_pages; i++) + update_mmu_tlb(vma, addr + PAGE_SIZE * i, vmf->pte + i); ret = VM_FAULT_NOPAGE; + goto unlock; } + folio_ref_add(folio, nr_pages - 1); + set_pte_range(vmf, folio, page, nr_pages, addr); + type = is_cow ? MM_ANONPAGES : mm_counter_file(folio); + add_mm_counter(vma->vm_mm, type, nr_pages); + ret = 0; + +unlock: pte_unmap_unlock(vmf->pte, vmf->ptl); return ret; } -- 2.39.3