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 X-Spam-Level: X-Spam-Status: No, score=-7.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8DCE9C35247 for ; Wed, 5 Feb 2020 16:22:40 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 549B4217BA for ; Wed, 5 Feb 2020 16:22:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 549B4217BA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DA7CD6E9C4; Wed, 5 Feb 2020 16:22:39 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id E3CF36E9C4 for ; Wed, 5 Feb 2020 16:22:38 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 08:22:38 -0800 X-IronPort-AV: E=Sophos;i="5.70,406,1574150400"; d="scan'208";a="224699930" Received: from aabader-mobl1.ccr.corp.intel.com (HELO [10.252.21.249]) ([10.252.21.249]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/AES256-SHA; 05 Feb 2020 08:22:37 -0800 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20200205121147.1834445-1-chris@chris-wilson.co.uk> <20200205121313.1834548-1-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <637ae604-f50d-7436-eb0b-e69d555e401f@linux.intel.com> Date: Wed, 5 Feb 2020 16:22:34 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200205121313.1834548-1-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH v2] drm/i915/gem: Don't leak non-persistent requests on changing engines X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 05/02/2020 12:13, Chris Wilson wrote: > If we have a set of active engines marked as being non-persistent, we > lose track of those if the user replaces those engines with > I915_CONTEXT_PARAM_ENGINES. As part of our uABI contract is that > non-persistent requests are terminated if they are no longer being > tracked by the user's context (in order to prevent a lost request > causing an untracked and so unstoppable GPU hang), we need to apply the > same context cancellation upon changing engines. > > Fixes: a0e047156cde ("drm/i915/gem: Make context persistence optional") > Testcase: XXX > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/gem/i915_gem_context.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > index 52a749691a8d..20f1d3e0221f 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > @@ -1624,11 +1624,18 @@ set_engines(struct i915_gem_context *ctx, > > replace: > mutex_lock(&ctx->engines_mutex); > + > + /* Flush stale requests off the old engines if required */ > + if (!i915_gem_context_is_persistent(ctx) || > + !i915_modparams.enable_hangcheck) > + kill_context(ctx); Is the negative effect of this is legit contexts can't keep submitting and changing the map? Only if PREEMPT_TIMEOUT is disabled I think but still. Might break legitimate userspace. Not that I offer solutions.. :( Banning changing engines once context went non-persistent? That too can break someone. Regards, Tvrtko > + > if (args->size) > i915_gem_context_set_user_engines(ctx); > else > i915_gem_context_clear_user_engines(ctx); > set.engines = rcu_replace_pointer(ctx->engines, set.engines, 1); > + > mutex_unlock(&ctx->engines_mutex); > > call_rcu(&set.engines->rcu, free_engines_rcu); > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx