From mboxrd@z Thu Jan 1 00:00:00 1970 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E08EEC433F5 for ; Mon, 11 Apr 2022 21:07:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349996AbiDKVKD (ORCPT ); Mon, 11 Apr 2022 17:10:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59454 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230074AbiDKVKB (ORCPT ); Mon, 11 Apr 2022 17:10:01 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4A2212AC70 for ; Mon, 11 Apr 2022 14:07:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649711265; 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=jemOUKtsQjTBQP4/G5H2AE4psd90cYA8xWnRCL9lC8M=; b=OuAzSa0kpB1s5fZB7f6neiEH/p/wh6Sb3jmcnkFUh60hwmClCUDkBy8mpVH6h4xgx8mlKD EEu8X4w8gSVU8iHuWCHgl9TKL0nF+AZdOmfDqnyz6pDZLPB1FaPrxgMjLPgOIdvdsMBrkB +dFPYuuPF8tYf+5qCaU7ETnqI9842Yw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-524-DJT_zkMEMjKrYjRkkS4JcQ-1; Mon, 11 Apr 2022 17:07:40 -0400 X-MC-Unique: DJT_zkMEMjKrYjRkkS4JcQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 5B49D85A5A8; Mon, 11 Apr 2022 21:07:39 +0000 (UTC) Received: from [10.18.17.215] (dhcp-17-215.bos.redhat.com [10.18.17.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id D8FBE40CF914; Mon, 11 Apr 2022 21:07:38 +0000 (UTC) Message-ID: <161c2e25-3d26-4dd7-d378-d1741f7bcca8@redhat.com> Date: Mon, 11 Apr 2022 17:07:38 -0400 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v5] locking/rwsem: Make handoff bit handling more consistent Content-Language: en-US To: john.p.donnelly@oracle.com, chenguanyou , gregkh@linuxfoundation.org Cc: dave@stgolabs.net, hdanton@sina.com, linux-kernel@vger.kernel.org, mazhenhua@xiaomi.com, mingo@redhat.com, peterz@infradead.org, quic_aiquny@quicinc.com, will@kernel.org, sashal@kernel.org References: <20211116012912.723980-1-longman@redhat.com> <20220214154741.12399-1-chenguanyou@xiaomi.com> <3f02975c-1a9d-be20-32cf-f1d8e3dfafcc@oracle.com> <31178c33-e25c-c3e8-35e2-776b5211200c@oracle.com> From: Waiman Long In-Reply-To: <31178c33-e25c-c3e8-35e2-776b5211200c@oracle.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/11/22 17:03, john.p.donnelly@oracle.com wrote: > >>> >>> I have reached out to Waiman and he suggested this for our next test >>> pass: >>> >>> >>> 1ee326196c6658 locking/rwsem: Always try to wake waiters in >>> out_nolock path >> >> Does this commit help to avoid the lockup problem? >> >> Commit 1ee326196c6658 fixes a potential missed wakeup problem when a >> reader first in the wait queue is interrupted out without acquiring >> the lock. It is actually not a fix for commit d257cc8cb8d5. However, >> this commit changes the out_nolock path behavior of writers by >> leaving the handoff bit set when the wait queue isn't empty. That >> likely makes the missed wakeup problem easier to reproduce. >> >> Cheers, >> Longman >> > > Hi, > > > We are testing now > > ETA for fio soak test completion is  ~15hr from now. > > I wanted to share the stack traces for future reference + occurrences. > I am looking forward to your testing results tomorrow. Cheers, Longman