From patchwork Tue Oct 8 02:18:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yihang Li X-Patchwork-Id: 13825558 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (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 975501EA73 for ; Tue, 8 Oct 2024 02:18:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728353912; cv=none; b=UqZkfK57+dZE6IjsFryd/WIGQk5OOIuLWIKjSVe0+ltSRTiVp9OiIgYogdkK8VMk1TNHjqfD7GOTU75sBwbA2sFz6b3LhllX4AIu0Gah6b2rM4ZGd5d1uF7kNevaQeasrbxdUQkxUOyyrarFgX8V1Gn1oBuJ+uK0WLjXfENqzs4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728353912; c=relaxed/simple; bh=kOfUPImhewwIXimCMyY3LqiKgugpisDlCmWObeNJRr4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QslKrMF3eOVMSNfPo2p2G1OUYpsPiM5l3cbTePvykk6q4NlPvzI4NuZENHs4BjbXz/MTMhFhzpV8et5nMy9GI4aVQVC1lm5Cer03zzFhSG0rGDMipC8RjrkNUETO/WbkHeVWopGmvhusItp/d9yP7q/6vLnz1Fk8DATw4PVFRlE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4XN04r3qbPzpWfR; Tue, 8 Oct 2024 10:16:28 +0800 (CST) Received: from dggpemf100013.china.huawei.com (unknown [7.185.36.179]) by mail.maildlp.com (Postfix) with ESMTPS id 9A3351403D5; Tue, 8 Oct 2024 10:18:28 +0800 (CST) Received: from localhost.huawei.com (10.50.165.33) by dggpemf100013.china.huawei.com (7.185.36.179) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 8 Oct 2024 10:18:28 +0800 From: Yihang Li To: , CC: , , Subject: [PATCH v2 07/13] scsi: hisi_sas: Add cond_resched() for no forced preemption model Date: Tue, 8 Oct 2024 10:18:16 +0800 Message-ID: <20241008021822.2617339-8-liyihang9@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20241008021822.2617339-1-liyihang9@huawei.com> References: <20241008021822.2617339-1-liyihang9@huawei.com> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemf100013.china.huawei.com (7.185.36.179) For no forced preemption model kernel, in the scenario where the expander is connected to 12 high performance SAS SSDs, the following call trace may occur: [ 214.409199][ C240] watchdog: BUG: soft lockup - CPU#240 stuck for 22s! [irq/149-hisi_sa:3211] [ 214.568533][ C240] pstate: 60400009 (nZCv daif +PAN -UAO -TCO BTYPE=--) [ 214.575224][ C240] pc : fput_many+0x8c/0xdc [ 214.579480][ C240] lr : fput+0x1c/0xf0 [ 214.583302][ C240] sp : ffff80002de2b900 [ 214.587298][ C240] x29: ffff80002de2b900 x28: ffff1082aa412000 [ 214.593291][ C240] x27: ffff3062a0348c08 x26: ffff80003a9f6000 [ 214.599284][ C240] x25: ffff1062bbac5c40 x24: 0000000000001000 [ 214.605277][ C240] x23: 000000000000000a x22: 0000000000000001 [ 214.611270][ C240] x21: 0000000000001000 x20: 0000000000000000 [ 214.617262][ C240] x19: ffff3062a41ae580 x18: 0000000000010000 [ 214.623255][ C240] x17: 0000000000000001 x16: ffffdb3a6efe5fc0 [ 214.629248][ C240] x15: ffffffffffffffff x14: 0000000003ffffff [ 214.635241][ C240] x13: 000000000000ffff x12: 000000000000029c [ 214.641234][ C240] x11: 0000000000000006 x10: ffff80003a9f7fd0 [ 214.647226][ C240] x9 : ffffdb3a6f0482fc x8 : 0000000000000001 [ 214.653219][ C240] x7 : 0000000000000002 x6 : 0000000000000080 [ 214.659212][ C240] x5 : ffff55480ee9b000 x4 : fffffde7f94c6554 [ 214.665205][ C240] x3 : 0000000000000002 x2 : 0000000000000020 [ 214.671198][ C240] x1 : 0000000000000021 x0 : ffff3062a41ae5b8 [ 214.677191][ C240] Call trace: [ 214.680320][ C240] fput_many+0x8c/0xdc [ 214.684230][ C240] fput+0x1c/0xf0 [ 214.687707][ C240] aio_complete_rw+0xd8/0x1fc [ 214.692225][ C240] blkdev_bio_end_io+0x98/0x140 [ 214.696917][ C240] bio_endio+0x160/0x1bc [ 214.701001][ C240] blk_update_request+0x1c8/0x3bc [ 214.705867][ C240] scsi_end_request+0x3c/0x1f0 [ 214.710471][ C240] scsi_io_completion+0x7c/0x1a0 [ 214.715249][ C240] scsi_finish_command+0x104/0x140 [ 214.720200][ C240] scsi_softirq_done+0x90/0x180 [ 214.724892][ C240] blk_mq_complete_request+0x5c/0x70 [ 214.730016][ C240] scsi_mq_done+0x48/0xac [ 214.734194][ C240] sas_scsi_task_done+0xbc/0x16c [libsas] [ 214.739758][ C240] slot_complete_v3_hw+0x260/0x760 [hisi_sas_v3_hw] [ 214.746185][ C240] cq_thread_v3_hw+0xbc/0x190 [hisi_sas_v3_hw] [ 214.752179][ C240] irq_thread_fn+0x34/0xa4 [ 214.756435][ C240] irq_thread+0xc4/0x130 [ 214.760520][ C240] kthread+0x108/0x13c [ 214.764430][ C240] ret_from_fork+0x10/0x18 This is because in the hisi_sas driver, both the hardware interrupt handler and the interrupt thread are executed on the same CPU. In the performance test scenario, function irq_wait_for_interrupt() will always return 0 if lots of interrupts occurs and the CPU will be continuously consumed. As a result, the CPU cannot run the watchdog thread. When the watchdog time exceeds the specified time, call trace occurs. To fix it, add cond_resched() to execute the watchdog thread. Signed-off-by: Yihang Li Reviewed-by: Xiang Chen --- drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c index 9e65ad0e6ce0..e6fbbefe9959 100644 --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c @@ -2493,6 +2493,7 @@ static int complete_v3_hw(struct hisi_sas_cq *cq) /* update rd_point */ cq->rd_point = rd_point; hisi_sas_write32(hisi_hba, COMPL_Q_0_RD_PTR + (0x14 * queue), rd_point); + cond_resched(); return completed; }