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=-7.5 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 A8A94C433E0 for ; Tue, 30 Jun 2020 14:16:54 +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 803642073E for ; Tue, 30 Jun 2020 14:16:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 803642073E 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 17A0A892C2; Tue, 30 Jun 2020 14:16:54 +0000 (UTC) Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by gabe.freedesktop.org (Postfix) with ESMTPS id 31DE7892C2 for ; Tue, 30 Jun 2020 14:16:52 +0000 (UTC) IronPort-SDR: C/xIICLMTQpqBxYGV1XmYi6+i++xadETuT5y1/lFdYvDZxJV9vfqgswv6P9QUBkLi2XXQke+/A P1IOg3SSCGtA== X-IronPort-AV: E=McAfee;i="6000,8403,9666"; a="133693408" X-IronPort-AV: E=Sophos;i="5.75,297,1589266800"; d="scan'208";a="133693408" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 07:16:51 -0700 IronPort-SDR: aH2V4NX3gv7d/TByczvLiu4zsoVnnpbZajbpcRN/sPvSH58t3Eu4JBWgz6u+AHZFRgFbjvwKAb VKYUyQsiiaYA== X-IronPort-AV: E=Sophos;i="5.75,297,1589266800"; d="scan'208";a="454622080" Received: from serbencx-mobl1.ger.corp.intel.com (HELO [10.252.49.157]) ([10.252.49.157]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 07:16:50 -0700 To: Maarten Lankhorst , intel-gfx@lists.freedesktop.org References: <20200623142843.423594-26-maarten.lankhorst@linux.intel.com> <20200624110515.454665-1-maarten.lankhorst@linux.intel.com> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: Date: Tue, 30 Jun 2020 15:16:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200624110515.454665-1-maarten.lankhorst@linux.intel.com> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH] drm/i915: Kill context before taking ctx->mutex 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 24/06/2020 12:05, Maarten Lankhorst wrote: > Killing context before taking ctx->mutex fixes a hang in > gem_ctx_persistence.close-replace-race, where lut_close > takes obj->resv.lock which is already held by execbuf, > causing a stalling indefinitely. If this is the consequence of inverting the locking order I think you need to move the fix earlier in the series, to precede the patch which creates the inversion. Otherwise AFAICT the re-order of kill_context vs lut_close seems fine. Regards, Tvrtko > [ 1904.342847] 2 locks held by gem_ctx_persist/11520: > [ 1904.342849] #0: ffff8882188e4968 (&ctx->mutex){+.+.}-{3:3}, at: context_close+0xe6/0x850 [i915] > [ 1904.342941] #1: ffff88821c58a5a8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: lut_close+0x2c2/0xba0 [i915] > [ 1904.343033] 3 locks held by gem_ctx_persist/11521: > [ 1904.343035] #0: ffffc900008ff938 (reservation_ww_class_acquire){+.+.}-{0:0}, at: i915_gem_do_execbuffer+0x103d/0x54c0 [i915] > [ 1904.343157] #1: ffff88821c58a5a8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: eb_validate_vmas+0x602/0x2010 [i915] > [ 1904.343267] #2: ffff88820afd9200 (&vm->mutex/1){+.+.}-{3:3}, at: i915_vma_pin_ww+0x335/0x2300 [i915] > > Signed-off-by: Maarten Lankhorst > --- > drivers/gpu/drm/i915/gem/i915_gem_context.c | 22 ++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > index a3519d5ee5a3..6d25c9c2be1a 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > @@ -623,6 +623,17 @@ static void context_close(struct i915_gem_context *ctx) > i915_gem_context_set_closed(ctx); > mutex_unlock(&ctx->engines_mutex); > > + /* > + * If the user has disabled hangchecking, we can not be sure that > + * the batches will ever complete after the context is closed, > + * keeping the context and all resources pinned forever. So in this > + * case we opt to forcibly kill off all remaining requests on > + * context close. > + */ > + if (!i915_gem_context_is_persistent(ctx) || > + !ctx->i915->params.enable_hangcheck) > + kill_context(ctx); > + > mutex_lock(&ctx->mutex); > > set_closed_name(ctx); > @@ -642,17 +653,6 @@ static void context_close(struct i915_gem_context *ctx) > > mutex_unlock(&ctx->mutex); > > - /* > - * If the user has disabled hangchecking, we can not be sure that > - * the batches will ever complete after the context is closed, > - * keeping the context and all resources pinned forever. So in this > - * case we opt to forcibly kill off all remaining requests on > - * context close. > - */ > - if (!i915_gem_context_is_persistent(ctx) || > - !ctx->i915->params.enable_hangcheck) > - kill_context(ctx); > - > i915_gem_context_put(ctx); > } > > > base-commit: 64cab0b9f9bfeb14d3ec2452d76b56915cdeb09f > prerequisite-patch-id: e6315738715ac4ffccaeb4c4bf5a94651fb8da1d > prerequisite-patch-id: 7944bb01d1ec7530513eabddb9198275653cc451 > prerequisite-patch-id: 052eda3b40906f0fbc16b4cc33dbcdce35e05441 > prerequisite-patch-id: 35ff18a74e8bf9bfb0a517f69a98d0ec88bd3b51 > prerequisite-patch-id: 7a34e785e951b1d3f4c0e20430c8111a15ddbe92 > prerequisite-patch-id: 9b7faf3172e9f218a2589fcc96930af9ab05e70b > prerequisite-patch-id: 3ce7c5b4508018631673e62d8725f866988bd08d > prerequisite-patch-id: 5fd46caff26e53f9cb6df5f8490838b6ac15e015 > prerequisite-patch-id: 41782208b1bc32e448ce29313112030c74bd8421 > prerequisite-patch-id: b6c4d99cb554c0c2268cde5c43e878a48e005e45 > prerequisite-patch-id: 418fdb031a232bba4056171917ee42e997991902 > prerequisite-patch-id: ff5bf0dcdb9191761392b0707481aaf99396dbec > prerequisite-patch-id: c3dbcef2f1a68f88ae99acbd01ee56847fb3e2da > prerequisite-patch-id: 18c373676c9bbeb1c11fb2ba5bf4ad728cfea75d > prerequisite-patch-id: 5b9d8e4535096365d365fdd1ec00f844a4135208 > prerequisite-patch-id: 63bac64548acd514c4a0cb5acb896c8217fb8201 > prerequisite-patch-id: e93b855dd97b24799c59f059cc548f46807ab207 > prerequisite-patch-id: 3d7dc6ecbc2279fb48f0972a911fbffd8d899faa > prerequisite-patch-id: f1d9e0b7165f80efe984dd0231d1dbd2a9a79950 > prerequisite-patch-id: ed1a168ac98b81b8066f68a0738cfc44a79e8ef1 > prerequisite-patch-id: f813cb8d4c2fe2c1d94b66c3f3fbb787ac241628 > prerequisite-patch-id: 0f0f90eaa4a2e299adddfe1c7134af3810a8e9e2 > prerequisite-patch-id: cb7ffeccd6429fc79aebffb84f62af5e78252461 > prerequisite-patch-id: 78905449b46ad574757a7fb91f58847ea20e09cd > prerequisite-patch-id: 6d937a49f3c8cd380121f72610072aaaf8c274b1 > prerequisite-patch-id: 0c8d2dee1592395780258488be0350755e7ffd7d > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx