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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EA0C0C9830E for ; Thu, 24 Sep 2026 15:44:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3mth+udyl4shJuTkd6p94FaAdssxMiU2m/RJPfhfFqY=; b=uyftIJnlDi5bwML/Cw50iOS2QN DXMev0CwxoA63Np70qP7tvl0mlUYigBT2nsspHdfqANa+53fzAJWxyLepvmJ074LRCFYunxXto8o+ 6WZa8VT8zaB5HIIT9DZN2hpIxzUts8LMcjyWS+ozuL7IDg7Zd3yBVKUPW1N0cBtqtHK2pQZFv8VfS XBmsqgeevxwEIbTamwah/4PJlHAVYUhA3V92J2xlDETWwbQ76w/aAcXJV6uN/USbEhrvWGlbhZDDb CV9J1E4MvKabDgY7S66i0IfYW+b4netmzAZMJrvC5cJj1GSWq7n6c95ef2+FPJbRORkKDpoXlASub lybO3KjQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9lcD-0000000BSy1-01hc; Thu, 24 Sep 2026 15:44:05 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9lc7-0000000BSxW-2Bjg for linux-nvme@lists.infradead.org; Thu, 24 Sep 2026 15:43:59 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id B543F601DE; Thu, 24 Sep 2026 15:43:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B3B01F000FF; Thu, 24 Sep 2026 15:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790264638; bh=3mth+udyl4shJuTkd6p94FaAdssxMiU2m/RJPfhfFqY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=Uns0tLZ94/wZQNd9IxDW++FfeLwvvbl/fmfWaGlUaXDd5grtwvV55NLgTxiG7FIWu iA0U2nPP4f4+LSQa9XXTIhDMMUsRbWur3PZVfXAMO28HdT3lTE4xPOugUd165Zems/ upYUjWSP2JkNKoi/YXdhAeQiLRnat4hqx9G9gmVHI/9RL1Iedn+uvUJIyCIidrwDxW ScN4GUNyO+JQbIgH75xqH8XO+AZNu17ON+2RLYDqqKtFq9BHKqx7763/2B4rBo8/ym kOZLcHssKDqM/1ADG5esDZKy0C+eZqFO3esE+iSCS3Kk9FXp+3ILaBsbu/xU6kXCc2 8dL1TGi5KQGiQ== Date: Thu, 24 Sep 2026 09:43:56 -0600 From: Keith Busch To: Krishna Iyer Cc: hare@suse.de, axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, nilay@linux.ibm.com, sjpark@crusoe.ai, saravanand@crusoe.ai Subject: Re: [PATCH v3] nvme-multipath: add fail_if_no_path sysfs attribute Message-ID: References: <20260923004959.88440-1-kiyer@crusoe.ai> <20260923225753.49224-1-kiyer@crusoe.ai> <20260924063524.26807-1-kiyer@crusoe.ai> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260924063524.26807-1-kiyer@crusoe.ai> X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Sep 23, 2026 at 11:35:24PM -0700, Krishna Iyer wrote: > Yes, exactly. Some namespaces should keep waiting out the reconnect > while others should stop waiting and fail their parked I/O, decided > by a condition only userspace can see. Here that condition is a > killed process stuck in D state on parked I/O that nothing will ever > consume (for us a SIGKILLed VM the host must reap), and it could be > any consumer known to be gone. Failing that namespace lets the > process exit, while namespaces with live users behind the same > controllers keep queueing and carry on when paths return. A > controller wide timeout cannot separate the two, and there is no > duration to pick up front since the trigger is userspace observing > the event. Reconnect itself is untouched either way. So the kernel > provides the per namespace switch and the decision stays in > userspace. Okay, I see. Pehaps instead of having one controller export all the namespaces, why not configure your target to have multiple subsystems the client makes independent connections to for each namespace?