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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 94E8DC4338F for ; Thu, 29 Jul 2021 14:06:44 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 5B94B60EBD for ; Thu, 29 Jul 2021 14:06:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 5B94B60EBD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F27B66ECCC; Thu, 29 Jul 2021 14:06:43 +0000 (UTC) Received: from mail-ot1-x32c.google.com (mail-ot1-x32c.google.com [IPv6:2607:f8b0:4864:20::32c]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0D1E66ECD0 for ; Thu, 29 Jul 2021 14:06:43 +0000 (UTC) Received: by mail-ot1-x32c.google.com with SMTP id c7-20020a9d27870000b02904d360fbc71bso5935577otb.10 for ; Thu, 29 Jul 2021 07:06:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=GQQzsyH/f6URg61tofzTvzb4mIeJR5g7C3j0V5QBWwQ=; b=ccbwg/bqYjVhkbLdaxvR8EM6zEzvGcGu7jr7OUsCCGSCnUW09Z3Opg1lve/8/IKAwN 8Fou8bwC9ssQMTDHd+l/VrFCF1mWwf+/KDB/03XJ3iP/eyXi47/rABfdm0EE4PW8oIJk fhKCnfC0U6DV4w+RwR/ndawzv56yVxsss6w0s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=GQQzsyH/f6URg61tofzTvzb4mIeJR5g7C3j0V5QBWwQ=; b=aUvhqB1a+6p/kHUjtyq/7rjoZOlq+Lb1iOmMd2cMbwfsz8laUyhCQBhFxaS5Ew3vMB A3PkmdeCpK5v2pIyYP56zBmBdOLxBKKcfOHyYTmWZA+fgVmwfUGZWgcbvcvbetRVrDxF RxBJUr7NJdp+DsfQ7vDtfMpUzW14LjwMGU4e2WNvhi34AcpP7YyWSUSw7XsNsohqAOAy 6cyupvUIvtCMhYZ4r/htELgVFxbOgYx9KbGo6/mkk07GPHCznRpWT05QuUzZnjZFCQWV JGQJ//WND3R9ioVCGdp+WAu8mLXvbuoFj5EW/HIZkB8xeduG+YR+51TF3UKs3y2O03NH XF1A== X-Gm-Message-State: AOAM532rYTJ/ENNlMx/QHPl8BI9qE/xDJhxSUMnp4TcaMR/jOdd5OmQy WC0P6vHItlRN3QDkMYRV+/HYIK0ER/kyJGILFYgaGg== X-Google-Smtp-Source: ABdhPJxbrM2UdOJP5RHayc+aBxFznHhjSEsliI4VDpONNANw9FR5U/edlulFU7nITKOLjQcHXMH3SpVmt5O6OM8J/RI= X-Received: by 2002:a9d:27a4:: with SMTP id c33mr3642364otb.281.1627567602332; Thu, 29 Jul 2021 07:06:42 -0700 (PDT) MIME-Version: 1.0 References: <20210729133420.770672-1-tvrtko.ursulin@linux.intel.com> <20210729133420.770672-2-tvrtko.ursulin@linux.intel.com> In-Reply-To: <20210729133420.770672-2-tvrtko.ursulin@linux.intel.com> From: Daniel Vetter Date: Thu, 29 Jul 2021 16:06:31 +0200 Message-ID: To: Tvrtko Ursulin Subject: Re: [Intel-gfx] [PATCH 2/2] drm/i915: Use Transparent Hugepages when IOMMU is enabled X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx , dri-devel , Chris Wilson , Matthew Auld , Eero Tamminen Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, Jul 29, 2021 at 3:34 PM Tvrtko Ursulin wrote: > > From: Tvrtko Ursulin > > Usage of Transparent Hugepages was disabled in 9987da4b5dcf > ("drm/i915: Disable THP until we have a GPU read BW W/A"), but since it > appears majority of performance regressions reported with an enabled IOMMU > can be almost eliminated by turning them on, lets just do that. > > To err on the side of safety we keep the current default in cases where > IOMMU is not active, and only when it is default to the "huge=within_size" > mode. Although there probably would be wins to enable them throughout, > more extensive testing across benchmarks and platforms would need to be > done. > > With the patch and IOMMU enabled my local testing on a small Skylake part > shows OglVSTangent regression being reduced from ~14% (IOMMU on versus > IOMMU off) to ~2% (same comparison but with THP on). > > v2: > * Add Kconfig dependency to transparent hugepages and some help text. > * Move to helper for easier handling of kernel build options. > > v3: > * Drop Kconfig. (Daniel) > > References: b901bb89324a ("drm/i915/gemfs: enable THP") > References: 9987da4b5dcf ("drm/i915: Disable THP until we have a GPU read BW W/A") > References: https://gitlab.freedesktop.org/drm/intel/-/issues/430 > Co-developed-by: Chris Wilson > Signed-off-by: Chris Wilson > Cc: Joonas Lahtinen > Cc: Matthew Auld > Cc: Eero Tamminen > Cc: Tvrtko Ursulin > Cc: Rodrigo Vivi > Cc: Daniel Vetter > Signed-off-by: Tvrtko Ursulin > Reviewed-by: Rodrigo Vivi # v1 On both patches: Acked-by: Daniel Vetter > --- > drivers/gpu/drm/i915/gem/i915_gemfs.c | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gemfs.c b/drivers/gpu/drm/i915/gem/i915_gemfs.c > index 5e6e8c91ab38..dbdbdc344d87 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gemfs.c > +++ b/drivers/gpu/drm/i915/gem/i915_gemfs.c > @@ -6,7 +6,6 @@ > > #include > #include > -#include > > #include "i915_drv.h" > #include "i915_gemfs.h" > @@ -15,6 +14,7 @@ int i915_gemfs_init(struct drm_i915_private *i915) > { > struct file_system_type *type; > struct vfsmount *gemfs; > + char *opts; > > type = get_fs_type("tmpfs"); > if (!type) > @@ -26,10 +26,26 @@ int i915_gemfs_init(struct drm_i915_private *i915) > * > * One example, although it is probably better with a per-file > * control, is selecting huge page allocations ("huge=within_size"). > - * Currently unused due to bandwidth issues (slow reads) on Broadwell+. > + * However, we only do so to offset the overhead of iommu lookups > + * due to bandwidth issues (slow reads) on Broadwell+. > */ > > - gemfs = kern_mount(type); > + opts = NULL; > + if (intel_vtd_active()) { > + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { > + static char huge_opt[] = "huge=within_size"; /* r/w */ > + > + opts = huge_opt; > + drm_info(&i915->drm, > + "Transparent Hugepage mode '%s'\n", > + opts); > + } else { > + drm_notice(&i915->drm, > + "Transparent Hugepage support is recommended for optimal performance when IOMMU is enabled!\n"); > + } > + } > + > + gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name, opts); > if (IS_ERR(gemfs)) > return PTR_ERR(gemfs); > > -- > 2.30.2 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx