From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 6FB3323535E for ; Wed, 26 Feb 2025 18:13:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740593618; cv=none; b=YOIWlR96z/PGDEkTvxxgcHHDWqAgEmF3l5+BUvljuwfNRzB5ITadRM/uVSZYp61xyJVk+guIORmZxD5lptPQav6rS9dRhtSQ7+qDNI4yLc/0pkyC3IXg0Cpek65BZEn2LVUGPaBzWBvoPWCHuyBQoO+7wFlHKJzG5HiObIVJ9d8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740593618; c=relaxed/simple; bh=XLAtlLUXwKK8ny06xKZ7zYu8j6udBGfXLlBXiJ9RE3k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=asPTkgVOp5PEt159MCE5X/Ewz241qdpZMDjNLObJZYbnoOr5b7sOh/mTjhxrBmWLXJ5YMA0StpAcxTkYC71QEM8JxC7KgIPnU+AImHIEENJYiEObBMpPnFm72wdWioQu5UClo71Ck0oUiePKTWbfEAxFcC1zdGDxx+LlwCcyqHc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=eD8qygok; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eD8qygok" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740593615; 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: in-reply-to:in-reply-to:references:references; bh=XLAtlLUXwKK8ny06xKZ7zYu8j6udBGfXLlBXiJ9RE3k=; b=eD8qygoknIa7TJ0Zmr7MuhWW9sVuOJxynya61fb5gAir+aCCcjyZ7Zk+kyLSQB8kf2yWix SIZtKwbL+8TatpFu/bM8bZ4iQ6Blt1ccjX87c6Vm1DaTehaIrT/L7Aij508WT5fQLFPB2v IN4kpwPWFdTHX/1QeVaI1o6tV0TgRV4= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-57-2kt4h1ThNnaDv1YG9PAUkg-1; Wed, 26 Feb 2025 13:13:22 -0500 X-MC-Unique: 2kt4h1ThNnaDv1YG9PAUkg-1 X-Mimecast-MFC-AGG-ID: 2kt4h1ThNnaDv1YG9PAUkg_1740593600 Received: from mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.15]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5EFC71800876; Wed, 26 Feb 2025 18:13:20 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.226.247]) by mx-prod-int-02.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 9F3EF19560B9; Wed, 26 Feb 2025 18:13:15 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 26 Feb 2025 19:12:50 +0100 (CET) Date: Wed, 26 Feb 2025 19:12:20 +0100 From: Oleg Nesterov To: "Sapkal, Swapnil" Cc: Manfred Spraul , Linus Torvalds , Christian Brauner , David Howells , WangYuli , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, K Prateek Nayak , "Shenoy, Gautham Ranjal" , Neeraj.Upadhyay@amd.com, mjguzik@gmail.com Subject: Re: [PATCH] pipe_read: don't wake up the writer if the pipe is still full Message-ID: <20250226181220.GJ8995@redhat.com> References: <20250102140715.GA7091@redhat.com> <20250224142329.GA19016@redhat.com> <20250225115736.GA18523@redhat.com> <2a0a8e1e-1c37-4655-8a82-54681b2a83ae@amd.com> <20250226113845.GB8995@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.15 On 02/26, Sapkal, Swapnil wrote: > > >Can you reproduce with "--process" rather than "--threads" ? > > > I was able to reproduce the issue with processes also. Total 33 processes > were sleeping out of which 20 were readers and 13 were writers. Thanks a lot. I am wondering what makes your machine (or .config?) special ;) A lot of people and robots tested this patch with these options. > The stack trace for main hackbench process is as follows: > > [<0>] do_wait+0xb5/0x110 Yes, this is clear, the main thread/process is not interesting. > I am trying to reproduce the issue with suggestions by Mateusz. Great. So far I still have no clue. Most probably I will ask you to do more testing after that, perhaps with some debugging patches. Thanks again for your help, Oleg.