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 41E75C44507 for ; Sat, 11 Jul 2026 02:56:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B4BD210F977; Sat, 11 Jul 2026 02:56:34 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="LxfhpiTv"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4D91110E2C3; Sat, 11 Jul 2026 02:56:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1783738590; x=1815274590; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=0Ygs/J+tJ2GUeHHaseAhNeLr6cTq7ecVyU2Iw8p25K4=; b=LxfhpiTv7qoKFy6c8UPlR/8rrDYp5GY7BukRBhn5wuU8vhw7Y3pfeu0Q c+eyFzJKOu5nbxnk5D6QKT+/t4G9ptJE4c9277UmevUdgIsmA5+RHt+Jb pUusNKrKmAAVBXwTzdvkSn8trAqrmAsNORaqDKRrcuVe0G9yCVFTTLkrg o0t8gl5Q2+engAv6aph4aZqT6ZkZTwNWKOMDLppxiLy1Gb93IO07HMeEp kX9JfJsXSdrxQ+QxYUUmYeko9Q6eayoqnnVSyB0c62J8DjDeKFBHYOYUu jE+r//uSsatlNErPPJ0phjGjw5YiARbQNmzPq0o7xxd/vL8ACqjVcZ4Ri w==; X-CSE-ConnectionGUID: 6hb3z0G/SEqGf4CzocTpcw== X-CSE-MsgGUID: yT6XDs7HQCObv6HHXNZTuw== X-IronPort-AV: E=McAfee;i="6800,10657,11841"; a="101986275" X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="101986275" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2026 19:56:29 -0700 X-CSE-ConnectionGUID: mRdUxlh3TnOtBCyoOvbXag== X-CSE-MsgGUID: 6kxmoT7iSYON26fKJBISag== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,154,1779174000"; d="scan'208";a="256987722" Received: from gsse-cloud1.jf.intel.com ([10.54.39.91]) by fmviesa004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jul 2026 19:56:28 -0700 From: Matthew Brost To: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Carlos Santa , Ryan Neph , Christian Koenig , Huang Rui , Matthew Auld , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , linux-kernel@vger.kernel.org, =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= Subject: [PATCH v3 16/33] drm/xe: Back off beneficial-order reclaim under defrag pressure Date: Fri, 10 Jul 2026 19:56:02 -0700 Message-Id: <20260711025619.2540575-17-matthew.brost@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260711025619.2540575-1-matthew.brost@intel.com> References: <20260711025619.2540575-1-matthew.brost@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" Once a meaningful number of BOs are already tracked as being backed at a sub-optimal order, continuing to push hard for beneficial-order pages during populate mostly wastes time in reclaim/compaction. In xe_ttm_tt_populate(), set ctx->beneficial_reclaim_backoff when the device defrag count reaches XE_BO_DEFRAG_RECLAIM_BACKOFF_THRESHOLD (2) so the TTM pool backs off and allocations make forward progress. The deferred defrag pass is responsible for upgrading these objects to beneficial order later. Cc: Carlos Santa Cc: Ryan Neph Cc: Christian Koenig Cc: Huang Rui Cc: Matthew Auld Cc: Maarten Lankhorst Cc: Maxime Ripard Cc: Thomas Zimmermann Cc: David Airlie Cc: Simona Vetter Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org Cc: Thomas Hellström Assisted-by: GitHub_Copilot:claude-opus-4.8 Signed-off-by: Matthew Brost --- drivers/gpu/drm/xe/xe_bo.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c index ff324caab6da..02395968d613 100644 --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -41,6 +41,14 @@ #include "xe_vm.h" #include "xe_vram_types.h" +/* + * Once this many BOs are tracked on the device defrag list (i.e. were backed + * with a sub-optimal page order), request that the TTM pool backs off from + * aggressive reclaim at the beneficial order during populate, so that + * allocations make forward progress instead of stalling. + */ +#define XE_BO_DEFRAG_RECLAIM_BACKOFF_THRESHOLD 2 + const char *const xe_mem_type_to_name[TTM_NUM_MEM_TYPES] = { [XE_PL_SYSTEM] = "system", [XE_PL_TT] = "gtt", @@ -598,6 +606,12 @@ static int xe_ttm_tt_populate(struct ttm_device *ttm_dev, struct ttm_tt *tt, if (ttm_tt_is_backed_up(tt) && !xe_tt->purgeable) { err = ttm_tt_restore(ttm_dev, tt, ctx); } else { + struct xe_device *xe = ttm_to_xe_device(ttm_dev); + + if (atomic_read(&xe->mem.defrag.count) >= + XE_BO_DEFRAG_RECLAIM_BACKOFF_THRESHOLD) + ctx->beneficial_reclaim_backoff = true; + ttm_tt_clear_backed_up(tt); err = ttm_pool_alloc(&ttm_dev->pool, tt, ctx); } -- 2.34.1