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 E9A08C531CA for ; Thu, 23 Jul 2026 13:35:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9FACC10E586; Thu, 23 Jul 2026 13:35:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="LrQViV+z"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) by gabe.freedesktop.org (Postfix) with ESMTPS id C61B110E586 for ; Thu, 23 Jul 2026 13:35:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1784813713; x=1816349713; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=MMs6aT2rYScWXOCNnVRxuzRAR5Oo0akRQoMpZfYOnTc=; b=LrQViV+zeSThIzWNhhy/HTfaO62OATt6mlJRD9EBC9AzJU2c9k1GAadF 1G9yknUp0xbcJln6/gM+r6c63Nka0on+yMrKMJorIGFme0FfR7vBi40xn 4xfj8Ib37bhNFyuZHoyYzr+9VGUDKp58cU0tQv5s8Y9q7HzM1fe7m4KNj WL+hXpggMFJy/itQ2d8ziLXIoa64ojr3+Wg4Hhv5kA9cwYPpVsXVjs7DT J52VRo+AwiH3QK6kwAYUoco3aNpTig5e0z+0zPzSfXnc/oQpYGM33MFPx 4eaqYIvWU8sQHwHIX1okKthhzIY3t/AyBPPxFsiStIZTj7h7UNfBBk/LE g==; X-CSE-ConnectionGUID: 7zQ4TRm2Qc63mO36mF8+hA== X-CSE-MsgGUID: 7v21Md5ASAal2Ld2t1W5Bg== X-IronPort-AV: E=McAfee;i="6800,10657,11854"; a="85318803" X-IronPort-AV: E=Sophos;i="6.25,180,1779174000"; d="scan'208";a="85318803" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jul 2026 06:35:12 -0700 X-CSE-ConnectionGUID: qulu8zs+QfiCD/ZMTdF3Bw== X-CSE-MsgGUID: tFV9mzXiS3en16RSkbz3pg== X-ExtLoop1: 1 Received: from abityuts-desk.ger.corp.intel.com (HELO mwauld-desk.intel.com) ([10.245.244.109]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Jul 2026 06:35:11 -0700 From: Matthew Auld To: intel-xe@lists.freedesktop.org Cc: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= , Matthew Brost Subject: [PATCH] drm/xe/bo: optimise TT population for DONTNEED BOs Date: Thu, 23 Jul 2026 14:34:19 +0100 Message-ID: <20260723133418.1201717-2-matthew.auld@intel.com> X-Mailer: git-send-email 2.55.0 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" When a VRAM buffer object is marked as DONTNEED, like in Mesa, the driver skips migrating its contents to system memory and instead purges the backing store during eviction (via xe_ttm_bo_purge). However, xe_evict_flags() still returns tt_placement (XE_PL_TT) for VRAM BOs even if they were marked DONTNEED. This causes ttm_bo_handle_move_mem() to call always call ttm_bo_populate() to allocate destination system pages, only for those pages to be immediately freed right after when xe_bo_move() calls xe_ttm_bo_purge(). Fix this by changing xe_evict_flags() to return sys_placement (XE_PL_SYSTEM) for DONTNEED BOs. This causes TTM to skip the population step while still ensuring that TTM calls xe_bo_move(), so xe_ttm_bo_purge() still triggers. Assisted-by: Copilot:gemini-3.1-pro-preview Signed-off-by: Matthew Auld Cc: Thomas Hellström Cc: Matthew Brost --- drivers/gpu/drm/xe/xe_bo.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c index c266fa6bade1..1daa80079608 100644 --- a/drivers/gpu/drm/xe/xe_bo.c +++ b/drivers/gpu/drm/xe/xe_bo.c @@ -341,6 +341,11 @@ static void xe_evict_flags(struct ttm_buffer_object *tbo, return; } + if (xe_bo_madv_is_dontneed(bo)) { + *placement = sys_placement; + return; + } + /* * For xe, sg bos that are evicted to system just triggers a * rebind of the sg list upon subsequent validation to XE_PL_TT. -- 2.55.0