From patchwork Thu Jun 27 00:39:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 13713565 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 71053C30653 for ; Thu, 27 Jun 2024 00:40:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 01D986B0092; Wed, 26 Jun 2024 20:40:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F0FB26B0095; Wed, 26 Jun 2024 20:40:54 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DFEA26B0096; Wed, 26 Jun 2024 20:40:54 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C210B6B0092 for ; Wed, 26 Jun 2024 20:40:54 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 67ADC121881 for ; Thu, 27 Jun 2024 00:40:54 +0000 (UTC) X-FDA: 82274813628.04.7AC278E Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf13.hostedemail.com (Postfix) with ESMTP id B4B2E2000B for ; Thu, 27 Jun 2024 00:40:52 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NvsK0GBO; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf13.hostedemail.com: domain of gshan@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=gshan@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1719448839; a=rsa-sha256; cv=none; b=tii6QY0+YCBebFs0b2z+tZsaLqKUsuyCIGjnvk6DF00GdU2BQqHOaxi4P2sDbEN7/UX4jF zcJQxLd7mBGgRHGHFt3Rr8gkdWHN0n9Gd7EZhzX0/w81CVNkqyKknLh+Wnhvm/GVuqONlM k6J1zmgNOOwekWcP8rTfy6Ua8A0Jf+c= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NvsK0GBO; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf13.hostedemail.com: domain of gshan@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=gshan@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1719448839; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=G9DtWlj69b/pnYrEaiiPgPbo2BCBiozg724qHNOyRaE=; b=jLOdFh6KbJBUE/PkX2DryHIRUQzI1TahCxzvvWNxnaGJbYgdPhBfvIWW3kF/3EPyELheM/ vM26ARErttRlaumoGQrTg4dSPrbY776cPKXt8MVB37SxLm+r9FjYFZKdnxqUuUOa5TKXf4 hPVfI9YcgQOqNXQKpjzi+4izvg2gKa0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719448852; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=G9DtWlj69b/pnYrEaiiPgPbo2BCBiozg724qHNOyRaE=; b=NvsK0GBOQe6GSG4mIV3dFaog9wCfVlC/X5p5cJEBZLY1tL07ta0lUc+TIpacaneKAn4wwD yjzT/JrQx4KuI5wDKcRP3j6R16ehNYJ8Ge/3A6lTlbGq+MPVhHlnAP9x/VooYy2367aU3p BE6xy/EOxcDu7mQaxWw5AX9yHuH80PM= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-609-T3HOp-fEOAyX71d8KoHjaQ-1; Wed, 26 Jun 2024 20:40:46 -0400 X-MC-Unique: T3HOp-fEOAyX71d8KoHjaQ-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5EF301956096; Thu, 27 Jun 2024 00:40:44 +0000 (UTC) Received: from gshan-thinkpadx1nanogen2.remote.csb (unknown [10.64.136.58]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 069C81956087; Thu, 27 Jun 2024 00:40:37 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, david@redhat.com, willy@infradead.org, akpm@linux-foundation.org, ryan.roberts@arm.com, hughd@google.com, william.kucharski@oracle.com, djwong@kernel.org, torvalds@linux-foundation.org, ddutile@redhat.com, zhenyzha@redhat.com, shan.gavin@gmail.com Subject: [PATCH v2 3/4] mm/filemap: Skip to create PMD-sized page cache if needed Date: Thu, 27 Jun 2024 10:39:51 +1000 Message-ID: <20240627003953.1262512-4-gshan@redhat.com> In-Reply-To: <20240627003953.1262512-1-gshan@redhat.com> References: <20240627003953.1262512-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: B4B2E2000B X-Stat-Signature: 95xsn94jz83738ux3o63oi35hmy9eha7 X-Rspam-User: X-HE-Tag: 1719448852-806085 X-HE-Meta: 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 n5sCqN3S JvAAsR/3olqurgJnuVq16mmVFB7OTcV2FIzZunyMYmyFkDbmZfnnBToBqwso2DcXfNvtXL7IDkT+tB4jpg5syW+FuFTOQ4gmSzvbPVpco0B9Mu7diZx5i86LaCyZYZsSKUzTN/Jpg8HUgM7w/8cIFcO0l7skfh0sAH7Oz5P9tgQdUvNy+FC/OcqVye9FbKl0JdNuvzL0NTiz7ejDpdn1JVPKYllVGaJ3UiEi/KIBHC9udNnoVONphxeKojAtDv8d0u3Bvgt1CfWkktkO3UYHsmecndc8Z4WQ7BcEJVdljYPs3s/zkDThQSpX4SsI9h94kEJsbF3pgKkVEhEk1uDUpAodMK4HeQdr/Lyh7o3EjflF9Q6WDaxsrappmcJHATSRahPsgZXxGqyie8vXTjWIcZ6MG2WjSkRNhV9HTURcvnmqpwwcQK3gngnjoIg== 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 ARM64, HPAGE_PMD_ORDER is 13 when the base page size is 64KB. The PMD-sized page cache can't be supported by xarray as the following error messages indicate. ------------[ cut here ]------------ WARNING: CPU: 35 PID: 7484 at lib/xarray.c:1025 xas_split_alloc+0xf8/0x128 Modules linked in: nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib \ nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct \ nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 \ ip_set rfkill nf_tables nfnetlink vfat fat virtio_balloon drm \ fuse xfs libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 \ sha1_ce virtio_net net_failover virtio_console virtio_blk failover \ dimlib virtio_mmio CPU: 35 PID: 7484 Comm: test Kdump: loaded Tainted: G W 6.10.0-rc5-gavin+ #9 Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20240524-1.el9 05/24/2024 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : xas_split_alloc+0xf8/0x128 lr : split_huge_page_to_list_to_order+0x1c4/0x720 sp : ffff800087a4f6c0 x29: ffff800087a4f6c0 x28: ffff800087a4f720 x27: 000000001fffffff x26: 0000000000000c40 x25: 000000000000000d x24: ffff00010625b858 x23: ffff800087a4f720 x22: ffffffdfc0780000 x21: 0000000000000000 x20: 0000000000000000 x19: ffffffdfc0780000 x18: 000000001ff40000 x17: 00000000ffffffff x16: 0000018000000000 x15: 51ec004000000000 x14: 0000e00000000000 x13: 0000000000002000 x12: 0000000000000020 x11: 51ec000000000000 x10: 51ece1c0ffff8000 x9 : ffffbeb961a44d28 x8 : 0000000000000003 x7 : ffffffdfc0456420 x6 : ffff0000e1aa6eb8 x5 : 20bf08b4fe778fca x4 : ffffffdfc0456420 x3 : 0000000000000c40 x2 : 000000000000000d x1 : 000000000000000c x0 : 0000000000000000 Call trace: xas_split_alloc+0xf8/0x128 split_huge_page_to_list_to_order+0x1c4/0x720 truncate_inode_partial_folio+0xdc/0x160 truncate_inode_pages_range+0x1b4/0x4a8 truncate_pagecache_range+0x84/0xa0 xfs_flush_unmap_range+0x70/0x90 [xfs] xfs_file_fallocate+0xfc/0x4d8 [xfs] vfs_fallocate+0x124/0x2e8 ksys_fallocate+0x4c/0xa0 __arm64_sys_fallocate+0x24/0x38 invoke_syscall.constprop.0+0x7c/0xd8 do_el0_svc+0xb4/0xd0 el0_svc+0x44/0x1d8 el0t_64_sync_handler+0x134/0x150 el0t_64_sync+0x17c/0x180 Fix it by skipping to allocate PMD-sized page cache when its size is larger than MAX_PAGECACHE_ORDER. For this specific case, we will fall to regular path where the readahead window is determined by BDI's sysfs file (read_ahead_kb). Fixes: 4687fdbb805a ("mm/filemap: Support VM_HUGEPAGE for file mappings") Cc: stable@kernel.org # v5.18+ Suggested-by: David Hildenbrand Signed-off-by: Gavin Shan Acked-by: David Hildenbrand --- mm/filemap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/filemap.c b/mm/filemap.c index 876cc64aadd7..b306861d9d36 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3124,7 +3124,7 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf) #ifdef CONFIG_TRANSPARENT_HUGEPAGE /* Use the readahead code, even if readahead is disabled */ - if (vm_flags & VM_HUGEPAGE) { + if ((vm_flags & VM_HUGEPAGE) && HPAGE_PMD_ORDER <= MAX_PAGECACHE_ORDER) { fpin = maybe_unlock_mmap_for_io(vmf, fpin); ractl._index &= ~((unsigned long)HPAGE_PMD_NR - 1); ra->size = HPAGE_PMD_NR; From patchwork Thu Jun 27 00:39:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gavin Shan X-Patchwork-Id: 13713566 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 6EC97C30653 for ; Thu, 27 Jun 2024 00:41:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F38D86B0096; Wed, 26 Jun 2024 20:41:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EE9436B0098; Wed, 26 Jun 2024 20:41:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D89EB6B0099; Wed, 26 Jun 2024 20:41:12 -0400 (EDT) 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 BA3F06B0096 for ; Wed, 26 Jun 2024 20:41:12 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 32A41C179C for ; Thu, 27 Jun 2024 00:41:12 +0000 (UTC) X-FDA: 82274814384.24.AE050E6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf02.hostedemail.com (Postfix) with ESMTP id 76E428000E for ; Thu, 27 Jun 2024 00:41:10 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cOcblj25; spf=pass (imf02.hostedemail.com: domain of gshan@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=gshan@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1719448862; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=1sMjn8/iFlaf4yeh2Uq+knpx1ch2OQwfa4RLnK7BL0o=; b=P2ZcWA4t2CrBT6FImbmna+Wur3LM3tHPOtzQ3kcqvOOQLoDbVckJD3Bd20nKD2qY3Nwr28 QpCc0Z2xVvOctk7BjzAtseH7v3HK8l6GoJ5KI+t9bW9sGEumkM5ozWjoqf983AUfaUU8r0 9uPa2Fs7hQSFWhu9zH7Jl8QBSjQDNlw= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cOcblj25; spf=pass (imf02.hostedemail.com: domain of gshan@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=gshan@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1719448862; a=rsa-sha256; cv=none; b=WqZzEM03CfxuXkUxuBA+zZv8IkuLEoqollOrwu9kQXKKUoHwMTJB6XMymkzUsuCxa+LQsT kOB/OD0A1yS5GHR1/WC6zSLx+LOlSVtkiDpd2h4iqvQdotvg5aBEgbrQQS0rPTLzgCXNPE Jje84V6UnhyZhjGoCvTF3panWF71E0M= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1719448864; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1sMjn8/iFlaf4yeh2Uq+knpx1ch2OQwfa4RLnK7BL0o=; b=cOcblj256+wKezNs7e+on2B9Z+zCFpokWtw5gfN3/b6iOPoGrG1V9aSugHUSOT6ADz0ppJ atlIEKLW/1ckPNyCEMi0+tbTBz/UmkfE8e7z6ZcafXU8orM9TfK5UfK9I7FXRmdjyTyefv 6taXjyeN3SMJrn7vlamfxsD5ugudVLg= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-438-IcPKpqm3NiyiViClxPbBgA-1; Wed, 26 Jun 2024 20:41:02 -0400 X-MC-Unique: IcPKpqm3NiyiViClxPbBgA-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5E7F2195608E; Thu, 27 Jun 2024 00:40:51 +0000 (UTC) Received: from gshan-thinkpadx1nanogen2.remote.csb (unknown [10.64.136.58]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 15F101956087; Thu, 27 Jun 2024 00:40:44 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, david@redhat.com, willy@infradead.org, akpm@linux-foundation.org, ryan.roberts@arm.com, hughd@google.com, william.kucharski@oracle.com, djwong@kernel.org, torvalds@linux-foundation.org, ddutile@redhat.com, zhenyzha@redhat.com, shan.gavin@gmail.com Subject: [PATCH v2 4/4] mm/shmem: Disable PMD-sized page cache if needed Date: Thu, 27 Jun 2024 10:39:52 +1000 Message-ID: <20240627003953.1262512-5-gshan@redhat.com> In-Reply-To: <20240627003953.1262512-1-gshan@redhat.com> References: <20240627003953.1262512-1-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 76E428000E X-Stat-Signature: no6pfwm4j8gy5u4aieirrb6x9r1oghqc X-HE-Tag: 1719448870-693593 X-HE-Meta: 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 UMNqywbA j+TjggkAWFsDxA/RwHW/NkCDteOTZ87Um8MVS9bLDOf4FNiG1GyvonwyPhU4RL/LWNIHep0TiCoPcp0AQhBj+kdd0QW/rpOD1wevz+W33c9B8CiBGGepnNhZx8CrZp6gAcOGG8bKE94dSIwZVqHNwrta7T78dQCuSeVRJZISg8DSDFxb8WgZsn6Q3xPjh4KhGr1BRaqLRLmxt1b+awkEIEHicjmqNlcoYoYWWpMGZDxYuY6I1VXU009F+w9j1NHs2dpI4D7s7k60P0mFjU5L9g75ZLpm8kTmM657JviOcO7LoSn84oQ6BO1k1b8UGYnvW0l3ivKRTQ9/57b4l3p7KAPvnkLoUbAg6pnOyR3OO0tXSJPHG/E8AWeJ/sz4CSS1mAGVTOf9HIqOAuH8Rtj5h70saR1s0vhRJY6pSJccYup1kSPmXE4lOpApnbA== 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: For shmem files, it's possible that PMD-sized page cache can't be supported by xarray. For example, 512MB page cache on ARM64 when the base page size is 64KB can't be supported by xarray. It leads to errors as the following messages indicate when this sort of xarray entry is split. WARNING: CPU: 34 PID: 7578 at lib/xarray.c:1025 xas_split_alloc+0xf8/0x128 Modules linked in: binfmt_misc nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 \ nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject \ nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 \ ip_set rfkill nf_tables nfnetlink vfat fat virtio_balloon drm fuse xfs \ libcrc32c crct10dif_ce ghash_ce sha2_ce sha256_arm64 sha1_ce virtio_net \ net_failover virtio_console virtio_blk failover dimlib virtio_mmio CPU: 34 PID: 7578 Comm: test Kdump: loaded Tainted: G W 6.10.0-rc5-gavin+ #9 Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20240524-1.el9 05/24/2024 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : xas_split_alloc+0xf8/0x128 lr : split_huge_page_to_list_to_order+0x1c4/0x720 sp : ffff8000882af5f0 x29: ffff8000882af5f0 x28: ffff8000882af650 x27: ffff8000882af768 x26: 0000000000000cc0 x25: 000000000000000d x24: ffff00010625b858 x23: ffff8000882af650 x22: ffffffdfc0900000 x21: 0000000000000000 x20: 0000000000000000 x19: ffffffdfc0900000 x18: 0000000000000000 x17: 0000000000000000 x16: 0000018000000000 x15: 52f8004000000000 x14: 0000e00000000000 x13: 0000000000002000 x12: 0000000000000020 x11: 52f8000000000000 x10: 52f8e1c0ffff6000 x9 : ffffbeb9619a681c x8 : 0000000000000003 x7 : 0000000000000000 x6 : ffff00010b02ddb0 x5 : ffffbeb96395e378 x4 : 0000000000000000 x3 : 0000000000000cc0 x2 : 000000000000000d x1 : 000000000000000c x0 : 0000000000000000 Call trace: xas_split_alloc+0xf8/0x128 split_huge_page_to_list_to_order+0x1c4/0x720 truncate_inode_partial_folio+0xdc/0x160 shmem_undo_range+0x2bc/0x6a8 shmem_fallocate+0x134/0x430 vfs_fallocate+0x124/0x2e8 ksys_fallocate+0x4c/0xa0 __arm64_sys_fallocate+0x24/0x38 invoke_syscall.constprop.0+0x7c/0xd8 do_el0_svc+0xb4/0xd0 el0_svc+0x44/0x1d8 el0t_64_sync_handler+0x134/0x150 el0t_64_sync+0x17c/0x180 Fix it by disabling PMD-sized page cache when HPAGE_PMD_ORDER is larger than MAX_PAGECACHE_ORDER. As Matthew Wilcox pointed, the page cache in a shmem file isn't represented by a multi-index entry and doesn't have this limitation when the xarry entry is split until commit 6b24ca4a1a8d ("mm: Use multi-index entries in the page cache"). Fixes: 6b24ca4a1a8d ("mm: Use multi-index entries in the page cache") Cc: stable@kernel.org # v5.17+ Signed-off-by: Gavin Shan Acked-by: David Hildenbrand --- mm/shmem.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index a8b181a63402..c1befe046c7e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -541,8 +541,9 @@ static bool shmem_confirm_swap(struct address_space *mapping, static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; -bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, - struct mm_struct *mm, unsigned long vm_flags) +static bool __shmem_is_huge(struct inode *inode, pgoff_t index, + bool shmem_huge_force, struct mm_struct *mm, + unsigned long vm_flags) { loff_t i_size; @@ -573,6 +574,16 @@ bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force, } } +bool shmem_is_huge(struct inode *inode, pgoff_t index, + bool shmem_huge_force, struct mm_struct *mm, + unsigned long vm_flags) +{ + if (HPAGE_PMD_ORDER > MAX_PAGECACHE_ORDER) + return false; + + return __shmem_is_huge(inode, index, shmem_huge_force, mm, vm_flags); +} + #if defined(CONFIG_SYSFS) static int shmem_parse_huge(const char *str) {