From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BBB3E78C7A; Fri, 16 Aug 2024 05:16:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723785416; cv=none; b=JOLiST38ba7ky5J7KbmLbxEfC+B1OlvD34zH1to/gFdTGiwBvnJo6yRkTlsVgBlp9cGWCNGMRPczPflJlHaa4drBrqQZpy4GihbSjKNuOrjakNltXNIVThISNURBvDV1YQzLSPb3jxT/zD9niG5n3OIDd3/D4QYOsF7TOrJ+Uxs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723785416; c=relaxed/simple; bh=Ox/EL5U1+Z8vk7aJGjY/0MfiqMn8bj4QbmKLNFXfIXg=; h=Date:To:From:Subject:Message-Id; b=E/DkY82VLRyjc2a+vMBiEVpZ+MS6VN+w71AtVNlTsBjvjLBm8UOQtQVd+vjJbp0dpZhyn44lBuFTZAXrTLQgSkZ31unTkuGUHRIHjltigt/pqA9xWE7z296+dQSkzyRGfs91w8vlq3p3XfnZc8sIMftwZ21FnE8m6IAMqzGMnnU= 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=CwCNvAjC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="CwCNvAjC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2AD82C4AF0B; Fri, 16 Aug 2024 05:16:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1723785416; bh=Ox/EL5U1+Z8vk7aJGjY/0MfiqMn8bj4QbmKLNFXfIXg=; h=Date:To:From:Subject:From; b=CwCNvAjCWtxqFYUnp86fKOeiP9t6ngBxOzFOpjf5J2Q0VNs06I4cV56huO9kYVnmE 2jA1XDfsoQ2T5MP4hbyKfjo+ofSsKxePxPuMS+7DGTFN9Kuy8q8Pdnlwq7zokXQob5 e8i2Hi00trjQ3ZrFJhg8Xn2DXbQQbPtcJFEZ/wsQ= Date: Thu, 15 Aug 2024 22:16:55 -0700 To: mm-commits@vger.kernel.org,ying.huang@intel.com,stable@vger.kernel.org,nao.horiguchi@gmail.com,linmiaohe@huawei.com,len.brown@intel.com,juri.lelli@redhat.com,longman@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-memory-failure-use-raw_spinlock_t-in-struct-memory_failure_cpu.patch removed from -mm tree Message-Id: <20240816051656.2AD82C4AF0B@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/memory-failure: use raw_spinlock_t in struct memory_failure_cpu has been removed from the -mm tree. Its filename was mm-memory-failure-use-raw_spinlock_t-in-struct-memory_failure_cpu.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Waiman Long Subject: mm/memory-failure: use raw_spinlock_t in struct memory_failure_cpu Date: Tue, 6 Aug 2024 12:41:07 -0400 The memory_failure_cpu structure is a per-cpu structure. Access to its content requires the use of get_cpu_var() to lock in the current CPU and disable preemption. The use of a regular spinlock_t for locking purpose is fine for a non-RT kernel. Since the integration of RT spinlock support into the v5.15 kernel, a spinlock_t in a RT kernel becomes a sleeping lock and taking a sleeping lock in a preemption disabled context is illegal resulting in the following kind of warning. [12135.732244] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 [12135.732248] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 270076, name: kworker/0:0 [12135.732252] preempt_count: 1, expected: 0 [12135.732255] RCU nest depth: 2, expected: 2 : [12135.732420] Hardware name: Dell Inc. PowerEdge R640/0HG0J8, BIOS 2.10.2 02/24/2021 [12135.732423] Workqueue: kacpi_notify acpi_os_execute_deferred [12135.732433] Call Trace: [12135.732436] [12135.732450] dump_stack_lvl+0x57/0x81 [12135.732461] __might_resched.cold+0xf4/0x12f [12135.732479] rt_spin_lock+0x4c/0x100 [12135.732491] memory_failure_queue+0x40/0xe0 [12135.732503] ghes_do_memory_failure+0x53/0x390 [12135.732516] ghes_do_proc.constprop.0+0x229/0x3e0 [12135.732575] ghes_proc+0xf9/0x1a0 [12135.732591] ghes_notify_hed+0x6a/0x150 [12135.732602] notifier_call_chain+0x43/0xb0 [12135.732626] blocking_notifier_call_chain+0x43/0x60 [12135.732637] acpi_ev_notify_dispatch+0x47/0x70 [12135.732648] acpi_os_execute_deferred+0x13/0x20 [12135.732654] process_one_work+0x41f/0x500 [12135.732695] worker_thread+0x192/0x360 [12135.732715] kthread+0x111/0x140 [12135.732733] ret_from_fork+0x29/0x50 [12135.732779] Fix it by using a raw_spinlock_t for locking instead. Also move the pr_err() out of the lock critical section and after put_cpu_ptr() to avoid indeterminate latency and the possibility of sleep with this call. [longman@redhat.com: don't hold percpu ref across pr_err(), per Miaohe] Link: https://lkml.kernel.org/r/20240807181130.1122660-1-longman@redhat.com Link: https://lkml.kernel.org/r/20240806164107.1044956-1-longman@redhat.com Fixes: 0f383b6dc96e ("locking/spinlock: Provide RT variant") Signed-off-by: Waiman Long Acked-by: Miaohe Lin Cc: "Huang, Ying" Cc: Juri Lelli Cc: Len Brown Cc: Naoya Horiguchi Cc: Signed-off-by: Andrew Morton --- mm/memory-failure.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) --- a/mm/memory-failure.c~mm-memory-failure-use-raw_spinlock_t-in-struct-memory_failure_cpu +++ a/mm/memory-failure.c @@ -2417,7 +2417,7 @@ struct memory_failure_entry { struct memory_failure_cpu { DECLARE_KFIFO(fifo, struct memory_failure_entry, MEMORY_FAILURE_FIFO_SIZE); - spinlock_t lock; + raw_spinlock_t lock; struct work_struct work; }; @@ -2443,20 +2443,22 @@ void memory_failure_queue(unsigned long { struct memory_failure_cpu *mf_cpu; unsigned long proc_flags; + bool buffer_overflow; struct memory_failure_entry entry = { .pfn = pfn, .flags = flags, }; mf_cpu = &get_cpu_var(memory_failure_cpu); - spin_lock_irqsave(&mf_cpu->lock, proc_flags); - if (kfifo_put(&mf_cpu->fifo, entry)) + raw_spin_lock_irqsave(&mf_cpu->lock, proc_flags); + buffer_overflow = !kfifo_put(&mf_cpu->fifo, entry); + if (!buffer_overflow) schedule_work_on(smp_processor_id(), &mf_cpu->work); - else + raw_spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); + put_cpu_var(memory_failure_cpu); + if (buffer_overflow) pr_err("buffer overflow when queuing memory failure at %#lx\n", pfn); - spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); - put_cpu_var(memory_failure_cpu); } EXPORT_SYMBOL_GPL(memory_failure_queue); @@ -2469,9 +2471,9 @@ static void memory_failure_work_func(str mf_cpu = container_of(work, struct memory_failure_cpu, work); for (;;) { - spin_lock_irqsave(&mf_cpu->lock, proc_flags); + raw_spin_lock_irqsave(&mf_cpu->lock, proc_flags); gotten = kfifo_get(&mf_cpu->fifo, &entry); - spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); + raw_spin_unlock_irqrestore(&mf_cpu->lock, proc_flags); if (!gotten) break; if (entry.flags & MF_SOFT_OFFLINE) @@ -2501,7 +2503,7 @@ static int __init memory_failure_init(vo for_each_possible_cpu(cpu) { mf_cpu = &per_cpu(memory_failure_cpu, cpu); - spin_lock_init(&mf_cpu->lock); + raw_spin_lock_init(&mf_cpu->lock); INIT_KFIFO(mf_cpu->fifo); INIT_WORK(&mf_cpu->work, memory_failure_work_func); } _ Patches currently in -mm which might be from longman@redhat.com are watchdog-handle-the-enodev-failure-case-of-lockup_detector_delay_init-separately.patch