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[23.128.96.18]) by mx.google.com with ESMTP id ov24si67005ejb.229.2020.08.20.17.37.55; Thu, 20 Aug 2020 17:38:43 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=NKVab9uj; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725834AbgHUAfU (ORCPT + 99 others); Thu, 20 Aug 2020 20:35:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726745AbgHUAfN (ORCPT ); Thu, 20 Aug 2020 20:35:13 -0400 Received: from mail-qk1-x72b.google.com (mail-qk1-x72b.google.com [IPv6:2607:f8b0:4864:20::72b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B9BB6C061386 for ; Thu, 20 Aug 2020 17:35:13 -0700 (PDT) Received: by mail-qk1-x72b.google.com with SMTP id j187so63955qke.11 for ; Thu, 20 Aug 2020 17:35:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:from:date:message-id:subject:to:cc; bh=9zlGc19T7gGaBdN6n4eVPyc5CgSkK4pVbFSDNM4cSJU=; b=NKVab9uj50c53P/eLsiWdZ2zQr13cC+OkC0jzOTQmvVmIwzpphzbsQqJlmg594pnlR zLq+RGU1kvFs/s8YNbWqwGS9BwqNDYXljo9G1SEpCp41rwhiVKa63F70smr6RxmZ/f/j zvLvotvEnN1fRZO6Yurf/Ox/W+dI19rQkKdS8svO+0hwGDd4Rk1icivefmDUvNF4x+t6 /iZEdBAeU+hQAQPM60orVIGwC80oY8w3qx5TmqnPpmfH3apA4B0Y/BH7XvkvBgFDX8IU MhRSchWVYoUnFSBMfZKGZMbSfbu1R9LvYdP01rbSLLAlEudg/B+Np55g5R2JAwelJ7u4 OwmA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=9zlGc19T7gGaBdN6n4eVPyc5CgSkK4pVbFSDNM4cSJU=; b=EVCMMDdGpLyiuoorKYF4YGzj9dTt+tBcN0J5mCbKLZdA2Tnum8x/74hHWcCIzZD2MU OVHSQ2pFNk9JZgm+/Kc2YvrOrfpvInJUafXUQgYdrxMYTNoFPv0u4x2/wsr6Bq1FrGf6 wAyKV6UjEzlXATCG5K1LvMVdftGszGQ8FXQwDVzXGrR1o/6fg/i9ShAUaAkw4wCPpuvF YyhYNOsXKC8KiJnGujJd+WscZYTbGBkP9d1lc6lktOLC86XE2dOHKzpCOaRFQzGk+4mQ Fb9MrnhKzT4D851IJp3QtirLUTBQ484harl1TsXtLSVuTCHUeUQP2nHqpKldNRz8PmfF JbaQ== X-Gm-Message-State: AOAM532SCEjahmwnErAJVY8ZwFxEMsJuLjeHHFj4DUjh2Z2U4NvH9uOb rios1FByhwqw3OwteuRU0M1+ULsOjXAb4rkiFBq6Ow== X-Received: by 2002:a05:620a:4ed:: with SMTP id b13mr529054qkh.493.1597970112174; Thu, 20 Aug 2020 17:35:12 -0700 (PDT) MIME-Version: 1.0 From: Khazhismel Kumykov Date: Thu, 20 Aug 2020 17:35:01 -0700 Message-ID: Subject: IOPRIO_CLASS_RT without CAP_SYS_ADMIN? To: axboe@kernel.dk, paolo.valente@linaro.org Cc: linux-block@vger.kernel.org, Linux Kernel Mailing List Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-256; boundary="000000000000ee4fc205ad5868f3" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --000000000000ee4fc205ad5868f3 Content-Type: text/plain; charset="UTF-8" It'd be nice to allow a process to send RT requests without granting it the wide capabilities of CAP_SYS_ADMIN, and we already have a capability which seems to almost fit this priority idea - CAP_SYS_NICE? Would this fit there? Being capable of setting IO priorities on per request or per thread basis (be it async submission or w/ thread ioprio_set) is useful especially when the userspace has its own prioritization/scheduling before hitting the kernel, allowing us to signal to the kernel how to order certain IOs, and it'd be nice to separate this from ADMIN for non-root processes, in a way that's less error prone than e.g. having a trusted launcher ionice the process and then drop priorities for everything but prio requests. khazhy --000000000000ee4fc205ad5868f3 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIPBgYJKoZIhvcNAQcCoIIO9zCCDvMCAQExDzANBglghkgBZQMEAgEFADALBgkqhkiG9w0BBwGg ggxpMIIEkjCCA3qgAwIBAgINAewckktV4F6Q7sAtGDANBgkqhkiG9w0BAQsFADBMMSAwHgYDVQQL ExdHbG9iYWxTaWduIFJvb3QgQ0EgLSBSMzETMBEGA1UEChMKR2xvYmFsU2lnbjETMBEGA1UEAxMK 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