From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 E0AEB267B1A for ; Tue, 25 Feb 2025 11:58:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740484703; cv=none; b=Bp1vHGqh/8JZNUAz3mDmNR7nbDAMMbxrFCCPni8T+HlormZBtDMvFbhJNqui8zYOacNnsWhCbab+S/HlmnugomqE0BvPVjJZAAfHAMWgHlrQuiCoOm0GOykmWAZaw2WE7xhSWwIAs0nhef8UaqHa6FTi4fzDq1ZKGhDw5sgKwg4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740484703; c=relaxed/simple; bh=ZML+M6SNb254B3okUsOvmT/4Q3X+djWXrWToFKbLH/I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IQZoqkioHS9DOg1o9c7+tQrOnzDnh7WFZRAg0zjHDN7lOB5DBTdMzx8HYaOeDcFe0CH6BK09hK4rgpI58mrGPF7047JJ+9RHA8zznHYoErfoefTfsUYtB59if/eg4/4yAKLcMvOyfrTfjuBlMYjtUV6yxWoQpgzJakknEY7qH3s= 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=deO5mD1n; arc=none smtp.client-ip=170.10.133.124 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="deO5mD1n" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740484700; 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=MCyJOCDY4s4V1OSV5l5wvh4COV+tZP6Tfm0smlf+8X4=; b=deO5mD1ne3YXzOTAXRJTevVLpdydrfbuBRYXHg5fIAN2vW3q92xDahbTu4tPcrqEVmXObJ dc+4LqR2tW5gzhPyvnOZt0FyTcEWGaV2MrLdSVPEiUyj1arCbL3B2wYGPNcEx3DJrUpdQG YIusBAhuJZjrQT16esoSvgEQ3EU2s50= 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-550-LiOX7p_OP_qs-CkJIUfpJQ-1; Tue, 25 Feb 2025 06:58:15 -0500 X-MC-Unique: LiOX7p_OP_qs-CkJIUfpJQ-1 X-Mimecast-MFC-AGG-ID: LiOX7p_OP_qs-CkJIUfpJQ_1740484693 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (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 49A9A1800879; Tue, 25 Feb 2025 11:58:13 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.211]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id EE376180035E; Tue, 25 Feb 2025 11:58:08 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 25 Feb 2025 12:57:43 +0100 (CET) Date: Tue, 25 Feb 2025 12:57:37 +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 Subject: Re: [PATCH] pipe_read: don't wake up the writer if the pipe is still full Message-ID: <20250225115736.GA18523@redhat.com> References: <20250102140715.GA7091@redhat.com> <20250224142329.GA19016@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: <20250224142329.GA19016@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 On 02/24, Oleg Nesterov wrote: > > Just in case, did you use > > https://git.kernel.org/pub/scm/utils/rt-tests/rt-tests.git/tree/src/hackbench/hackbench.c > > ? Or did you use another version? Exactly what parameters did you use? If possible, please reproduce the hang again. How many threads/processes sleeping in pipe_read() or pipe_write() do you see? (you can look at /proc/$pid/stack). Please pick one sleeping writer, and do $ strace -p pidof_that_write this should wake this writer up. If a missed wakeup is the only problem, hackbench should continue. The more info you can provide the better ;) Oleg.