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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7AEFEB64DB for ; Wed, 14 Jun 2023 13:22:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244958AbjFNNWf (ORCPT ); Wed, 14 Jun 2023 09:22:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244955AbjFNNWd (ORCPT ); Wed, 14 Jun 2023 09:22:33 -0400 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76CBA1FC4 for ; Wed, 14 Jun 2023 06:22:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1686748949; x=1718284949; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=krZlgUF812lZ1Msg1luNdv0RZ6yxrI7AK5Nw8giEATI=; b=C4tJIhV0VCe4TfWi1AwrH0pLBrKS7JAJc6wzGrVZnb+2N83Gn4nUS/G2 q9YzV0myxKR31BOY4EVZ/Llh6FFN3MnIevi97NKniYJuY8fz10zhmi+5P rc8uAAHZyyTLM+IPb8jJrJU4dEbF30isJMCTEiVsUKHj9SCi8ZBOCpm1d ZN6toUbni0DDY7s4LhpDcRZ8LjByNBXL0zry8zWrUSmajyJ1mGWcLj7N9 9wLbCeT38xwQAH10a09DqDfkkXuK2UnPsNqtkMfee0vbGyge0axeXwpl0 gc8rAkhKMQJ0D3WLtgJU8JrfRmuqRjy7ZAen20/f+ddSPe15XSkzVox3U A==; X-IronPort-AV: E=McAfee;i="6600,9927,10741"; a="444977887" X-IronPort-AV: E=Sophos;i="6.00,242,1681196400"; d="scan'208";a="444977887" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2023 06:22:29 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10741"; a="801899074" X-IronPort-AV: E=Sophos;i="6.00,242,1681196400"; d="scan'208";a="801899074" Received: from sobyrne-mobl1.ger.corp.intel.com (HELO [10.213.224.182]) ([10.213.224.182]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jun 2023 06:22:25 -0700 Message-ID: Date: Wed, 14 Jun 2023 14:22:23 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH] drm/i915: Call page_address() on page acquired with GFP_KERNEL flag Content-Language: en-US To: Sumitra Sharma , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , David Airlie , Daniel Vetter , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: Ira Weiny , Fabio , Deepak R Varma , Thomas Hellstrom , Matthew Auld References: <20230614123556.GA381200@sumitra.com> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc In-Reply-To: <20230614123556.GA381200@sumitra.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 14/06/2023 13:35, Sumitra Sharma wrote: > Pages allocated with GFP_KERNEL cannot come from Highmem. > That is why there is no need to call kmap() on them. Are you sure it is GFP_KERNEL backed and not tmpfs? I am not sure myself so let me copy Matt and Thomas if they happen to know off hand. Regards, Tvrtko > Therefore, don't call kmap() on the page coming from > vma_res->bi.pages using for_each_sgt_page() in > i915_vma_coredump_create(). > > Use a plain page_address() to get the kernel address instead. > > Signed-off-by: Sumitra Sharma > --- > drivers/gpu/drm/i915/i915_gpu_error.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c > index f020c0086fbc..6f51cb4fc55c 100644 > --- a/drivers/gpu/drm/i915/i915_gpu_error.c > +++ b/drivers/gpu/drm/i915/i915_gpu_error.c > @@ -1164,9 +1164,8 @@ i915_vma_coredump_create(const struct intel_gt *gt, > > drm_clflush_pages(&page, 1); > > - s = kmap(page); > + s = page_address(page); > ret = compress_page(compress, s, dst, false); > - kunmap(page); > > drm_clflush_pages(&page, 1); >