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=-11.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 83E7BC2B9F4 for ; Mon, 14 Jun 2021 12:46:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 628E961241 for ; Mon, 14 Jun 2021 12:46:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233291AbhFNMsv (ORCPT ); Mon, 14 Jun 2021 08:48:51 -0400 Received: from mail-pf1-f182.google.com ([209.85.210.182]:33563 "EHLO mail-pf1-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232992AbhFNMsq (ORCPT ); Mon, 14 Jun 2021 08:48:46 -0400 Received: by mail-pf1-f182.google.com with SMTP id p13so10498179pfw.0 for ; Mon, 14 Jun 2021 05:46:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:mime-version:content-disposition; bh=0WPH3hjxXBLsSpR7DWHsVJlt9dhkg5b/9bT0LLsWmo0=; b=ZG0sX2lQCF9+s9b3JXRpSAFu3a+dyqh8u264TEvZUod7aE9f7jmj/EcQtCQPMSy0XU q6V7ZIImpi3E4fyA4Sgl32befqpBoWLXMb1r31el8SdtftiIZLABolBoM/f0gtTrTe8O Pp+DGQd18YckizMSqdAorKKGWdRxkJtnvgcCw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:mime-version :content-disposition; bh=0WPH3hjxXBLsSpR7DWHsVJlt9dhkg5b/9bT0LLsWmo0=; b=n4DXVf8iEdw8eB26B1ULQ3a7/pcNf3/+I45taAMISjBsDDfzu0KWzlQ+s2Z1f8jt+c oRM8rlEOH6YOFcLYDyhJkCvMelVSYZEeJEAUxqz88GgHCMYHDIiRjvExCSjHxM9PJhIX 79Q8owtuN6Sy+x8KjE3R6CtQUQuXNWuXSJzsa4ZnLxsZ/JSVWlF4dJlS0DHTN+5GETMW Bd7LUNY9lHtV2VPNZxpqA5N7k6SHpyY4SNcrsQLwq/MAGbkYaN+wNRklYulSwiis7Xj+ o443BZT2ZtPwMQ0U3ptZ3y4iB5UH4TQK2bdyTu9BqXzf9QQV3LKrDdLCZnOIqwcJwMi0 vHEg== X-Gm-Message-State: AOAM530jEAsp7rIWClfKC74QWFyDTHudbuy6/JMWBhhxtGPwuohoY5Re d6GZJnDmbi0OP4DqkOFHCmh77A== X-Google-Smtp-Source: ABdhPJyVl60sQemzfpMYfU7sBdra5ITiOkMCODvou3wJumVZHT15gIThHUNcK01ELLsBz9W2sLkV1Q== X-Received: by 2002:a63:3ec3:: with SMTP id l186mr16665906pga.371.1623674743459; Mon, 14 Jun 2021 05:45:43 -0700 (PDT) Received: from google.com ([2409:10:2e40:5100:f64:2ecb:b3c0:fd80]) by smtp.gmail.com with ESMTPSA id mi10sm16609030pjb.10.2021.06.14.05.45.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Jun 2021 05:45:42 -0700 (PDT) Date: Mon, 14 Jun 2021 21:45:37 +0900 From: Sergey Senozhatsky To: Jani Nikula , Joonas Lahtinen , Daniel Vetter , David Airlie , Chris Wilson Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: drm/i915: __GFP_RETRY_MAYFAIL allocations in stable kernels Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, We are observing some user-space crashes (sigabort, segfaults etc.) under moderate memory pressure (pretty far from severe pressure) which have one thing in common - restrictive GFP mask in setup_scratch_page(). For instance, (stable 4.19) drivers/gpu/drm/i915/i915_gem_gtt.c (trimmed down version) static int gen8_init_scratch(struct i915_address_space *vm) { setup_scratch_page(vm, __GFP_HIGHMEM); vm->scratch_pt = alloc_pt(vm); vm->scratch_pd = alloc_pd(vm); if (use_4lvl(vm)) { vm->scratch_pdp = alloc_pdp(vm); } } gen8_init_scratch() function puts a rather inconsistent restrictions on mm. Looking at it line by line: setup_scratch_page() uses very restrictive gfp mask: __GFP_HIGHMEM | __GFP_ZERO | __GFP_RETRY_MAYFAIL it doesn't try to reclaim anything and fails almost immediately. alloc_pt() - uses more permissive gfp mask: GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN alloc_pd() - likewise: GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN alloc_pdp() - very permissive gfp mask: GFP_KERNEL So can all allocations in gen8_init_scratch() use GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN ? E.g. --- diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index a12430187108..e862680b9c93 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -792,7 +792,7 @@ alloc_pdp(struct i915_address_space *vm) GEM_BUG_ON(!use_4lvl(vm)); - pdp = kzalloc(sizeof(*pdp), GFP_KERNEL); + pdp = kzalloc(sizeof(*pdp), I915_GFP_ALLOW_FAIL); if (!pdp) return ERR_PTR(-ENOMEM); @@ -1262,7 +1262,7 @@ static int gen8_init_scratch(struct i915_address_space *vm) { int ret; - ret = setup_scratch_page(vm, __GFP_HIGHMEM); + ret = setup_scratch_page(vm, GFP_KERNEL | __GFP_HIGHMEM); if (ret) return ret; @@ -1972,7 +1972,7 @@ static int gen6_ppgtt_init_scratch(struct gen6_hw_ppgtt *ppgtt) u32 pde; int ret; - ret = setup_scratch_page(vm, __GFP_HIGHMEM); + ret = setup_scratch_page(vm, GFP_KERNEL | __GFP_HIGHMEM); if (ret) return ret; @@ -3078,7 +3078,7 @@ static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size) return -ENOMEM; } - ret = setup_scratch_page(&ggtt->vm, GFP_DMA32); + ret = setup_scratch_page(&ggtt->vm, GFP_KERNEL | GFP_DMA32); if (ret) { DRM_ERROR("Scratch setup failed\n"); /* iounmap will also get called at remove, but meh */ --- It's quite similar on stable 5.4 - setup_scratch_page() uses restrictive gfp mask again. --- diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index f614646ed3f9..99d78b1052df 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1378,7 +1378,7 @@ static int gen8_init_scratch(struct i915_address_space *vm) return 0; } - ret = setup_scratch_page(vm, __GFP_HIGHMEM); + ret = setup_scratch_page(vm, GFP_KERNEL | __GFP_HIGHMEM); if (ret) return ret; @@ -1753,7 +1753,7 @@ static int gen6_ppgtt_init_scratch(struct gen6_ppgtt *ppgtt) struct i915_page_directory * const pd = ppgtt->base.pd; int ret; - ret = setup_scratch_page(vm, __GFP_HIGHMEM); + ret = setup_scratch_page(vm, GFP_KERNEL | __GFP_HIGHMEM); if (ret) return ret; @@ -2860,7 +2860,7 @@ static int ggtt_probe_common(struct i915_ggtt *ggtt, u64 size) return -ENOMEM; } - ret = setup_scratch_page(&ggtt->vm, GFP_DMA32); + ret = setup_scratch_page(&ggtt->vm, GFP_KERNEL | GFP_DMA32); if (ret) { DRM_ERROR("Scratch setup failed\n"); /* iounmap will also get called at remove, but meh */ ---