From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f226.google.com (mail-il1-f226.google.com [209.85.166.226]) (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 2BC11202C5C for ; Tue, 18 Mar 2025 21:58:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.226 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742335123; cv=none; b=PLWl5x0ZKUcEmyKdotMJGqAitR/VLszfCDZjr/QRUWWUH3s6QjCwsHKbRkj7PvfFgdYOBMtExozp62To01HeoIVM1MvJKRL+3INvXBclGX+5xDwwpTk4nnuV6ClJWRfc2v5SKTkJX219NoFz/DCKkEZ2LwHDXFSqbufW5oxfpDM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742335123; c=relaxed/simple; bh=FNOlOnKPTmoDLF/ixHDn/TzCbzcrb8utOwuiWY5hpWA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=vDJRISbVCDDeKFacV2IKXuIuerMyfNSNzy1lbmRHYaIribBhY6eS4uexvaCcM9+LEQWzi5L3jTt1lyjfwQtciI1mhZWKj1YMfvveeIQarwQCd5mk5Iv0KpKiaOJ5IQusSrmfQ9aoJ/2zCnLwxgUifJklflLmUiztziHiqzhxEDE= 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=IzC14sa7; arc=none smtp.client-ip=209.85.166.226 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="IzC14sa7" Received: by mail-il1-f226.google.com with SMTP id e9e14a558f8ab-3d44369e87aso374665ab.1 for ; Tue, 18 Mar 2025 14:58:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1742335120; x=1742939920; 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=yx3ZT83Sw/P9UkLE21bhz44X65U7VubHeSIX9oQCM98=; b=IzC14sa7wtXAvbvaKXncFgHXF4grPE9eNuCRf//kau1C2tLvNK1lEUv/vJzooy1ZL6 GuGX8649emGHDbC2OQOo4R6EcOY5bQ+RRs0/c7oN5JkTqU9umugdzjC4pulfGyGOoUsr QyPMVrcZikp6ylpwD5dOmj5j91sP46t610WzeB6/zuOdrSpz9rVn/F6M5ijKJkyDjYHy APQZ6VKU4xEfAkD98XtxH+DGIoIglSd913PsOWEMSeeaKHe5JfF78qT9SaJ/U1q3T+sO w4V/BTLyy/1pLyFV/bJtJQyLNGpHQUM7QtrGKef1apobhAXCCNAnKfbVLR+9GBbErm3G Rc8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742335120; x=1742939920; 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=yx3ZT83Sw/P9UkLE21bhz44X65U7VubHeSIX9oQCM98=; b=PXfvdxeAtusYw2Xfnwvqc1LST18DNXv5AfKOhZj3SpRm9bZqUJng9BkPzDalkBqojv l/JNNVfIDX+MWDvkioXfw4X1OqNuJb+qEBYISUFKTLvTO9VWyGtd5amB9FLK01gYq+mM lzmA35t2zVqFSC509Ocs+qHspmsxlWPUxurLcFrZw6oqZ63/LobyMNvijtvJwel6MXUD 7PbT3JMSzmgbBKpRT5C1uqQY/O2787kdBMTade6OE3rsLXMxKVFsDqIcC50pHx48OH1P 1+3vau2LM2djV/rB8XDVSi6A0ZwSU5SnvVVzQG8mV8dAeJFMYWZb+rwBhG0WS471jvEI Pohg== X-Forwarded-Encrypted: i=1; AJvYcCXKq50QNeEQNNmCBgiLvymMvn7k87tRvsrillwYOOEJj5bUe37xGCFPaCeUaMM+ZwJ24bceEloVRWutMQ==@vger.kernel.org X-Gm-Message-State: AOJu0YzI2KeMWvEFNksWtSYJJFEAoArm3AfkC9F02pRt2swFf34dF2pi Q9hg8CqtOBOrel7G6uTM7G897fUDd2CsMChgvqeYc3LKArX9KDxlOlR/cCWeQMc4IYxjGBXBd06 gJPQudJwsQd/Qrw8qfK/P24x2YPa8j4jI X-Gm-Gg: ASbGncse6beXYcJEAqCjxKQnjDDVZ+ttvelMfd1BMOqAS6ZjbSh6DbGglCpV5qJojEQ Rva0kLg7XncruMYOKAqxdXRovNTIcSsrQYrIKIyoFeUonm/9UosRMQ4J9NHIsX+ZAtlqZPFbc3W ozJNi74fis01rezNj3UeO3w7sXxCJ2Q2+kR9zvJPODvYLKDb35o2/cyQscegFjwN5E90sqXu8ii lxeN5XphHiCwsix7DMO60ISrqN66MYwU62Kz5RmmGENjYRZtiIMFwN66psog0oWK1Xedk4pj9Bh u0dDOcIfEXHq2SD4FLNgfSd3hnvdrxTWAAfWd6a/y9SSVGbNGw== X-Google-Smtp-Source: AGHT+IECvniETaGhCeEpj9MhYKxcwDE74kf5vAb4l+lxw+2Z9R92wfP9az5nmgsH4mfe0p/fxsSqnM5lsGrw X-Received: by 2002:a05:6e02:20c6:b0:3d4:6e3a:4659 with SMTP id e9e14a558f8ab-3d586dae129mr3889215ab.1.1742335120214; Tue, 18 Mar 2025 14:58:40 -0700 (PDT) Received: from c7-smtp-2023.dev.purestorage.com ([208.88.159.128]) by smtp-relay.gmail.com with ESMTPS id e9e14a558f8ab-3d47a68593asm7574825ab.40.2025.03.18.14.58.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Mar 2025 14:58:40 -0700 (PDT) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev-ushankar.dev.purestorage.com [IPv6:2620:125:9007:640:7:70:36:0]) by c7-smtp-2023.dev.purestorage.com (Postfix) with ESMTP id B42A4340338; Tue, 18 Mar 2025 15:58:38 -0600 (MDT) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id A8733E400CB; Tue, 18 Mar 2025 15:58:38 -0600 (MDT) Date: Tue, 18 Mar 2025 15:58:38 -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> <097f0495-b2e8-4938-9a0d-c321f618d49b@kernel.dk> 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: <097f0495-b2e8-4938-9a0d-c321f618d49b@kernel.dk> On Tue, Mar 18, 2025 at 12:48:44PM -0600, Jens Axboe wrote: > > though I don't see any examples of drivers using it. Would it be a bad > > idea to try and reuse that? > > We can't reuse that one, and it's not for driver use - purely internal. > But I _think_ you could easily grab space in the union that has the hash > and ipi_list for it. And then you could dump needing this extra data per > request. Another idea is to union the refcount with end_io_data, since that's purely for the driver. But it might be a bit weird to tell drivers that they can use either end_io/end_io_data or the refcount but not both... not to mention it could be a nice exploit vector if drivers get it wrong. Either way, I think this work is follow-on material and shouldn't be rolled into this patch.