From patchwork Mon Feb 22 15:18:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Gordon X-Patchwork-Id: 8378721 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 597979F314 for ; Mon, 22 Feb 2016 15:20:27 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 85962204EB for ; Mon, 22 Feb 2016 15:20:26 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id DE1E220340 for ; Mon, 22 Feb 2016 15:20:23 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id C7D716E222; Mon, 22 Feb 2016 15:20:21 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 3E2EF890F7 for ; Mon, 22 Feb 2016 15:19:05 +0000 (UTC) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 22 Feb 2016 07:18:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,485,1449561600"; d="scan'208";a="918506588" Received: from dsgordon-linux2.isw.intel.com ([10.102.226.88]) by orsmga002.jf.intel.com with ESMTP; 22 Feb 2016 07:18:42 -0800 From: Dave Gordon To: intel-gfx@lists.freedesktop.org Date: Mon, 22 Feb 2016 15:18:28 +0000 Message-Id: <1456154308-9342-4-git-send-email-david.s.gordon@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1456154308-9342-1-git-send-email-david.s.gordon@intel.com> References: <1456154308-9342-1-git-send-email-david.s.gordon@intel.com> Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ Subject: [Intel-gfx] [PATCH v4 3/3] drm/i915: optimise i915_gem_object_vmap_range() for small objects X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that we use this function for ringbuffers and other "small" objects, it's worth avoiding an extra kmalloc()/kfree() cycle if the page array is small enough to put on the stack. Here we've chosen an arbitrary cutoff of 32 (4k) pages, which is big enough for a ringbuffer (4 pages) or a context image (currently up to 22 pages). Signed-off-by: Dave Gordon Cc: Tvrtko Ursulin Cc: Alex Dai Cc: Chris Wilson --- drivers/gpu/drm/i915/i915_gem.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 14942cf..effb69b 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2422,6 +2422,7 @@ void *i915_gem_object_vmap_range(struct drm_i915_gem_object *obj, unsigned int npages) { struct sg_page_iter sg_iter; + struct page *mypages[32]; struct page **pages; void *addr; int i; @@ -2431,10 +2432,16 @@ void *i915_gem_object_vmap_range(struct drm_i915_gem_object *obj, return NULL; } - pages = drm_malloc_ab(npages, sizeof(*pages)); - if (pages == NULL) { - DRM_DEBUG_DRIVER("Failed to get space for pages\n"); - return NULL; + if (npages <= ARRAY_SIZE(mypages)) + pages = mypages; + else { + pages = kmalloc(npages*sizeof(*pages), GFP_TEMPORARY | __GFP_NOWARN); + if (pages == NULL) + pages = drm_malloc_ab(npages, sizeof(*pages)); + if (pages == NULL) { + DRM_DEBUG_DRIVER("Failed to get space for pages\n"); + return NULL; + } } i = 0; @@ -2447,7 +2454,8 @@ void *i915_gem_object_vmap_range(struct drm_i915_gem_object *obj, addr = vmap(pages, npages, 0, PAGE_KERNEL); if (addr == NULL) DRM_DEBUG_DRIVER("Failed to vmap pages\n"); - drm_free_large(pages); + if (pages != mypages) + drm_free_large(pages); return addr; }