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Wed, 11 Feb 2026 22:32:30 -0800 (PST) Received: from google.com ([2a00:79e0:2031:6:725d:f34:4b56:7316]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35662f6bbe9sm8028461a91.12.2026.02.11.22.32.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Feb 2026 22:32:29 -0800 (PST) Date: Thu, 12 Feb 2026 15:32:25 +0900 From: Sergey Senozhatsky To: "David Hildenbrand (Arm)" Cc: Sergey Senozhatsky , Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCHv2] mm: khugepaged: make scan loops suspend aware Message-ID: References: <20260211031512.261127-1-senozhatsky@chromium.org> <104bc764-5a20-4ac2-95a8-b31f41255766@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <104bc764-5a20-4ac2-95a8-b31f41255766@kernel.org> X-Rspamd-Queue-Id: 3CD8DC000D X-Stat-Signature: ura14miijzfrbor4897re4dfoefbfpur X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1770877951-524322 X-HE-Meta: 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 8esmsgB2 gWHgiYelyiB8qvGLtpDOgNfFfmGAcKzms0OrfiYqa5lWLVGN+b5E26rEip5WE15jluIG5E8keVr9LA/Na3rJh8fFlJZsADRF0uKq8TFAVOlhYHZy+rnkp89BK/qPvG4VX1P0vi9jW8v2E7ZjmJszJ8Am2eam0KiTpUwBPrIK8qDFHNAdHpvLhgp6aDddBvYg95SVISQQBWUvN7AKDiNZRU+B97uLWbx2bU3k9EyQbsOrOjk9OJ/m3jp7gVxFmSrX4QypcBHoZcev7ReUqkKrC1W5uyhdBo0aLu1eQBms3XJuENaLvEe+B1gutyOIHwoJl6vaaEa1Fp68YlAwifXF2KgQoYhR75Ftl7ix0MTmS3E23Upc= 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 (26/02/11 10:50), David Hildenbrand (Arm) wrote: > On 2/11/26 04:15, Sergey Senozhatsky wrote: > > A number of khugepaaged's loops, e.g. khugepaged_scan_mm_slot(), > > are time unbound, which can become problematic during system > > suspend: > > > > PM: suspend entry (s2idle) > > Filesystems sync: 0.003 seconds > > Freezing user space processes > > Freezing user space processes completed (elapsed 0.003 seconds) > > OOM killer disabled. > > Freezing remaining freezable tasks > > Freezing remaining freezable tasks failed after 20.004 seconds (1 tasks refusing to freeze, wq_busy=0): > > task:khugepaged state:D stack:0 pid:1345 ppid:2 flags:0x00004000 > > Call Trace: > > > > schedule+0x523/0x16a0 > > schedule_timeout+0x23b/0x6e0 > > io_schedule_timeout+0x3f/0x80 > > wait_for_completion_io_timeout+0xe4/0x170 > > submit_bio_wait+0x79/0xc0 > > swap_readpage+0x150/0x2d0 > > swap_cluster_readahead+0x3be/0x750 > > shmem_swapin+0xa7/0x100 > > shmem_swapin_folio+0xcd/0x2e0 > > shmem_get_folio+0x237/0x580 > > collapse_file+0x247/0x1280 > > hpage_collapse_scan_file+0x26e/0x380 > > khugepaged+0x43b/0x810 > > kthread+0xfb/0x120 > > > > > > Make hpage_collapse_test_exit_or_disable() suspend aware so > > that khugepaaged's scan loops can terminate in a timely manner > > and let system enter the sleep state. > > > > Do we want a Fixes: tag, and maybe backport this to stable kernels? I can Cc stable, but I don't know about Fixes - we are adding something that was never there, not fixing a regression.