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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 2DE73C433EF for ; Fri, 8 Apr 2022 09:51:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 3733D10EEFF; Fri, 8 Apr 2022 09:50:59 +0000 (UTC) Received: from mail-ej1-x62e.google.com (mail-ej1-x62e.google.com [IPv6:2a00:1450:4864:20::62e]) by gabe.freedesktop.org (Postfix) with ESMTPS id D920010EF3E; Fri, 8 Apr 2022 09:50:57 +0000 (UTC) Received: by mail-ej1-x62e.google.com with SMTP id bq8so16179074ejb.10; Fri, 08 Apr 2022 02:50:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=UTDP5PxuJrNhtwiIw4kPX3oornzx0fZUq1ACNZdju5g=; b=oSzOmpZ+P66fuPaE0vyi8SUeW9IBkGVgrCfg2WtxLRjCFyFBI+PN3wXaNfFZWSpyL2 3bPRWlApOdFalecgK1ltupG8ZnnagEh5pMlrsy/DIKG7EChbPbJ66IdU4srfD7OuBw1g bGSWN0fnoMnu/rL7+VSj0BtCta1WiCkqxNwqVnDTkH9SxRpH5Yt5kPS5ZGBdmNHe6yOZ sKK7X0An9d8BXqS/AhOFC6hvqpxy61XbfQ6ZqIskb6F92Jc4Fk14Gr8Gz7gOp/DGJJ/J TNm15y7O7cCIP7g5/USWI7lPcYlmlie6pmS9nlzxO7yc0kXm1+1JNOWtmmHnYwtmqUCI YFLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=UTDP5PxuJrNhtwiIw4kPX3oornzx0fZUq1ACNZdju5g=; b=nYT6VjO+Cqg9VDD0Xpp1zGiiSfqVl/am7TJOMG/csxQhPo+3OaVSyZErGX8EOhD75V tGtEIoCQnoCjiuNgr3dQPGT634FR08Wqi9SGFG0zyI2VrNtDz2whDKttwMwcU9A5INfo 7WPxdKzBsqnMCNgdzOuY5uxH5kS2ZpZUx2jVU7zVpOm5X82kguk/a5HcYFZlido0z96C Df9j/yb1+6vsc4idqkSQ9Qa2vuPeX2cUVFbfTrCDA941GuuATYQsvkI1k26oxc/WQ8k7 s4CZLFw3JMsZUe3hT+6w3c+BiecZIjetPvkvBu6SHDHHWJuCriLnr6P8RhhuWxFfAeyq MO6w== X-Gm-Message-State: AOAM53299BGgkNCarWZ/Ip1EUkMYPa7mj1fVfvXQG10I3v4ALWrKEHkC 2yfzfrIOEi3B63qVr47qe1S+vSJliBbFDiHxzTM= X-Google-Smtp-Source: ABdhPJyAoQKrVZDAh1z+M8F5kkP4azVx+dQWCPnP3y8cew9bhU+ZQlwfEvMyF8THi53mytdvPyU1H4sO+NPpuc7vyMk= X-Received: by 2002:a17:906:478b:b0:6db:8b6e:d5de with SMTP id cw11-20020a170906478b00b006db8b6ed5demr18052634ejc.161.1649411456228; Fri, 08 Apr 2022 02:50:56 -0700 (PDT) MIME-Version: 1.0 References: <20220407151627.3387655-1-tvrtko.ursulin@linux.intel.com> <20220407151627.3387655-2-tvrtko.ursulin@linux.intel.com> In-Reply-To: From: Dave Airlie Date: Fri, 8 Apr 2022 19:50:45 +1000 Message-ID: Subject: Re: [PATCH 1/1] drm/i915: Inherit submitter nice when scheduling requests To: Tvrtko Ursulin Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Intel Graphics Development , dri-devel , Tvrtko Ursulin Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, 8 Apr 2022 at 18:25, Tvrtko Ursulin wrote: > > > On 08/04/2022 08:58, Daniel Vetter wrote: > > On Thu, Apr 07, 2022 at 04:16:27PM +0100, Tvrtko Ursulin wrote: > >> From: Tvrtko Ursulin > >> > >> Inherit submitter nice at point of request submission to account for long > >> running processes getting either externally or self re-niced. > >> > >> This accounts for the current processing landscape where computational > >> pipelines are composed of CPU and GPU parts working in tandem. > >> > >> Nice value will only apply to requests which originate from user contexts > >> and have default context priority. This is to avoid disturbing any > >> application made choices of low and high (batch processing and latency > >> sensitive compositing). In this case nice value adjusts the effective > >> priority in the narrow band of -19 to +20 around > >> I915_CONTEXT_DEFAULT_PRIORITY. > >> > >> This means that userspace using the context priority uapi directly has a > >> wider range of possible adjustments (in practice that only applies to > >> execlists platforms - with GuC there are only three priority buckets), but > >> in all cases nice adjustment has the expected effect: positive nice > >> lowering the scheduling priority and negative nice raising it. > >> > >> Signed-off-by: Tvrtko Ursulin > > > > I don't think adding any more fancy features to i915-scheduler makes > > sense, at least not before we've cut over to drm/sched. > > Why do you think so? > > Drm/sched has at least low/normal/high priority and surely we will keep > the i915 context priority ABI. > > Then this patch is not touching the i915 scheduler at all, neither it is > fancy. > > The cover letter explains how it implements the same approach as the IO > scheduler. And it explains the reasoning and benefits. Provides an user > experience benefit today, which can easily be preserved. won't this cause uAPI divergence between execlists and GuC, like if something nices to -15 or -18 with execlists and the same with GuC it won't get the same sort of result will it? Dave.