From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 E6E6D4848A5; Tue, 13 Oct 2026 04:33:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791866011; cv=none; b=DcmcNo54h2lLNWcRLK9ppVCQffhic8UTPWnnv4wxTST97363f/fqithSthgCYX1pxv+VTOklRNjPfBpwqsWyJlaE9eGbVu6JNaALrb1xNaTMH3VLXu6BgE63K4ojiObKE8o0+2dGQfXuRBR30++JuRLJoWejlbqf9snjbrmkUFI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791866011; c=relaxed/simple; bh=LxU5Juz9kSoqD0JyDxlyA2S0m3BQNUtI8AF5u6M1LmI=; h=Date:To:From:Subject:Message-Id; b=HWBYn4qdGrskugJmTG2On5zts12blJPCDPAdizkhZRytxtKrezuFIBW60nrH5A2YmB84AhXmj7NQqjNjG/2umijz4aa0ZOgiXlpZGyJ+RiuvZMk3JAghiXc5F14ma9kDLI16rQCGlfi/l2JLVIcGRbej5J+y/BDkv7oXiqH3yhs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Pigmyr0m; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Pigmyr0m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BBF1D1F00893; Tue, 13 Oct 2026 04:33:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1791866009; bh=J/7QxNrBYn49lJF+FgAThlNSHL0e9GGvl5xudSqUi28=; h=Date:To:From:Subject; b=Pigmyr0m18Ci+FAums8/akpRnQM2b2cvd1mDr5Ig/DkI1ZZ0+sY0BMRH74tC9jXad 7rSrXFFltiSs5O628oP2JRB7ob7G5g0XtTvip/bzzgcxDe31ByapDc7aBn32zoc+Ll URuMQW3Zsg5179oqpTnQmhpE5Of6CQkOrDFzVbPw= Date: Mon, 12 Oct 2026 21:33:29 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,paulmck@kernel.org,hughd@google.com,baolin.wang@linux.alibaba.com,leitao@debian.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-shmem-report-rcu-tasks-quiescent-states-while-undoing-a-range.patch removed from -mm tree Message-Id: <20261013043329.BBF1D1F00893@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/shmem: report RCU-tasks quiescent states while undoing a range has been removed from the -mm tree. Its filename was mm-shmem-report-rcu-tasks-quiescent-states-while-undoing-a-range.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Breno Leitao Subject: mm/shmem: report RCU-tasks quiescent states while undoing a range Date: Fri, 18 Sep 2026 04:24:37 -0700 This shows up in the Meta fleet on ftruncate() of large tmpfs files: INFO: rcu_tasks detected stalls on tasks: 00000000752fd185: .. nvcsw: 59455/59455 holdout: 1 idle_cpu: -1/0 task:rocksdb:bottom state:R running task __folio_split find_get_entry find_get_entries truncate_inode_partial_folio shmem_undo_range shmem_setattr notify_change do_ftruncate __x64_sys_ftruncate do_syscall_64 shmem_undo_range() walks the whole of the requested range in folio_batch sized steps, twice, and its two cond_resched() calls are the only reschedule points in that walk. cond_resched() is not an RCU-tasks quiescent state. Use cond_resched_tasks_rcu_qs() at both points so the walk reports an RCU-tasks quiescent state as it proceeds. Link: https://lore.kernel.org/20260918-shmem-tasks-rcu-v1-1-79acf91a2569@debian.org Fixes: 8315f42295d2 ("rcu: Add call_rcu_tasks()") Signed-off-by: Breno Leitao Signed-off-by: Andrew Morton Reviewed-by: SJ Park Cc: Baolin Wang Cc: Hugh Dickins Cc: "Paul E . McKenney" Cc: --- mm/shmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/mm/shmem.c~mm-shmem-report-rcu-tasks-quiescent-states-while-undoing-a-range +++ a/mm/shmem.c @@ -1367,7 +1367,7 @@ static void shmem_undo_range(struct inod } folio_batch_remove_exceptionals(&fbatch); folio_batch_release(&fbatch); - cond_resched(); + cond_resched_tasks_rcu_qs(); } /* @@ -1408,7 +1408,7 @@ whole_folios: index = start; while (index < end) { - cond_resched(); + cond_resched_tasks_rcu_qs(); if (!find_get_entries(mapping, &index, end - 1, &fbatch, indices)) { _ Patches currently in -mm which might be from leitao@debian.org are