From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f99.google.com (mail-pj1-f99.google.com [209.85.216.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 550EB1DE2C8 for ; Tue, 18 Mar 2025 18:43:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.99 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742323426; cv=none; b=cA41ehiU8lOcK1Ne0QkznHZQ5mCn3rhfDHLYnwLcIozVMViXUgccebtsVCQWMCgK9Zt+5ZWQNXNvmun3e1OswTnzJ2ljoBKgoaC4edcf/YnOJgAYmTiyeN1+ydiYpaz8t3Iz1Dn0u2Y0CJ8b3X+IgK5hzDRCFLUknaG7VBmzLKg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742323426; c=relaxed/simple; bh=UwaP24eoj7BAO8Lak2j51EcNk4KY03aM+kQNAApp+2U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VqK9eynCf28Sp2WpPXHBNuTMcENTjgH2VWVZ8UfxdpBR+cUHV8COJehHXss0WNgxSJ/E2qbD+K9z58aq024ny1/4bx3uXsI5PGQ1HWqOCcDioBgeAPtGJqiRVVNXE8m4OgWWQTsNa4Rm1aAhUv8RGx/uGmzTxCW7grK4g9lGehk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com; spf=fail smtp.mailfrom=purestorage.com; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b=gnb3AEZn; arc=none smtp.client-ip=209.85.216.99 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=purestorage.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=purestorage.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=purestorage.com header.i=@purestorage.com header.b="gnb3AEZn" Received: by mail-pj1-f99.google.com with SMTP id 98e67ed59e1d1-2ff4a4f901fso6160730a91.2 for ; Tue, 18 Mar 2025 11:43:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1742323423; x=1742928223; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=TsMwNq6dS1d3ieUrbOI/pA+aTYiJTlgfP0K+Ojk0RDc=; b=gnb3AEZncd6fbKF7mJfq/jXKUoJck0nos13CCoBrhyOPv/McfWG0zlh81qkobpt1Lk BSDlYbXjbLt+1hwS68CI/NmZQXVEGvUyCz/b5NSmqXF/TSgPmO06oKw1DwkVUNSRPRXA WzOlm30MB6OqVjXIFEbXgq4rF+7W2y2Z8+aq/zAS/UZrflXVdyvcCohFNPGd2xfgCWgp FLa70uf4TtI+4vL9SsF/LJX/Xz/g9Vnw8c2Najmp+P2U9OxExCirEtphiBa4gcLpcsNS mTQVgVbu+OTPPg2eadkkMVIM4DH2IeNUtmLCCf0Kl/l24stMGNwz/joLWtKKTV24FrrK dPrA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742323423; x=1742928223; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TsMwNq6dS1d3ieUrbOI/pA+aTYiJTlgfP0K+Ojk0RDc=; b=lAlydoqzm9HaR4lhfk8n6zO0op+0FFzCgVMVfhpDKjN3xGGBOhLgoYJ9mcGBKzqq4Y NvQPUaeA/8ODedHvx+42ZiZTbBDh3y+mpiwT+wJacLGu1MrAHAuRmnC6kNdeNb//Pn5E 8XfKrsRh3P7AIMyklSQpXQLqYEIUYMA5W9/bqXCNxnP0k+m2I7u67wa5qtAPReFaJkAm Emh1ceWSD1ITThpN5IKwaggxT2w1aFPwbEXxIpo4JNM4NXJPftDAEFNaQfP1Zl7qI5WV JrKtDEsqh25IlHMZFPjsTYIXtQztsVHbU/06R6hD3jujc/TyHZF5ZkGQVIDto0IdHnIg qfTg== X-Forwarded-Encrypted: i=1; AJvYcCWU0Rqor0iRueAJmPxSdKSOb5SmPuxcKsylvG8Yjs6fSJ+bw+5w4uyLdirb/IBmJG+sILOTLgj+uO284Q==@vger.kernel.org X-Gm-Message-State: AOJu0YywJOXIdTFzQD/I+k2RzIGZfdqilKM2zRc/Rx5s7y6Fs6xkCU6e tu2AS/0D69y1oZZcmZePlJZvK68PfAO562aeH/zhLpCB/cQsJgIEQgWEIf2j6zYa8WB2kc3pI9N EnZtDn99x3RktZBWZzjq9YRkT0f4b1Jht X-Gm-Gg: ASbGncsA+vJmKC3GtDih/Nz0fuUN6scd2e8lswhGtpiGTOB852ikiAz/KuYwpmfye6J q7GBDgMd/C/ACg/0OH8Opu4lPF6pvy5OT3J02bwS/t5FHxZqHlYpsc7zMPAXpORmmulXT1sLMCL +msAP2q6VkkusPNQSgYPFK2I1zcnRNgTJrZj9kjRLVhTF/c/IlJ4piJBzQNtfMJvky+yXfnWMnZ URId79LA87r3zuA+PIJM/H/D5Of+XWmTWhOnlbf5k+3e6p85vVgXa385PsdMWlGhG3rx0cZRAP7 hv/vMVm2c8K4LcEVgD8LAD+i8U80WDezemLp9YZTfzh9/4/HLA== X-Google-Smtp-Source: AGHT+IFWTk06yMJSEhTtZps4nH0pFGVLFfy6gG/Estl8Ef6TsMtY6Cf1VyHXIYrxQl1YrKtf7FtRTkEzgHAZ X-Received: by 2002:a17:90b:388b:b0:2ff:4e90:3c55 with SMTP id 98e67ed59e1d1-301a5b87b52mr4252334a91.27.1742323423509; Tue, 18 Mar 2025 11:43:43 -0700 (PDT) Received: from c7-smtp-2023.dev.purestorage.com ([208.88.159.129]) by smtp-relay.gmail.com with ESMTPS id 98e67ed59e1d1-3015374e6f6sm752584a91.15.2025.03.18.11.43.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Mar 2025 11:43:43 -0700 (PDT) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev-ushankar.dev.purestorage.com [10.7.70.36]) by c7-smtp-2023.dev.purestorage.com (Postfix) with ESMTP id BE5923404BD; Tue, 18 Mar 2025 12:43:42 -0600 (MDT) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id B2B86E4020B; Tue, 18 Mar 2025 12:43:42 -0600 (MDT) Date: Tue, 18 Mar 2025 12:43:42 -0600 From: Uday Shankar To: Jens Axboe Cc: Ming Lei , linux-block@vger.kernel.org Subject: Re: [PATCH] ublk: remove io_cmds list in ublk_queue Message-ID: References: <20250318-ublk_io_cmds-v1-1-c1bb74798fef@purestorage.com> Precedence: bulk X-Mailing-List: linux-block@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: On Tue, Mar 18, 2025 at 12:22:57PM -0600, Jens Axboe wrote: > > struct ublk_rq_data { > > - struct llist_node node; > > - > > struct kref ref; > > }; > > Can we get rid of ublk_rq_data then? If it's just a ref thing, I'm sure > we can find an atomic_t of space in struct request and avoid it. Not a > pressing thing, just tossing it out there... Yeah probably - we do need a ref since one could complete a request concurrently with another code path which references it (user copy and zero copy). I see that struct request has a refcount in it already, though I don't see any examples of drivers using it. Would it be a bad idea to try and reuse that?