From patchwork Wed Aug 16 13:58:44 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Cooper X-Patchwork-Id: 9903909 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BDAC360231 for ; Wed, 16 Aug 2017 14:01:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AF6D628A08 for ; Wed, 16 Aug 2017 14:01:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A36EA28A15; Wed, 16 Aug 2017 14:01:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A1C4128A09 for ; Wed, 16 Aug 2017 14:01:03 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dhyqS-0007ZI-71; Wed, 16 Aug 2017 13:58:52 +0000 Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dhyqQ-0007Z2-HX for xen-devel@lists.xen.org; Wed, 16 Aug 2017 13:58:50 +0000 Received: from [85.158.139.211] by server-15.bemta-5.messagelabs.com id 6E/9A-01736-99F44995; Wed, 16 Aug 2017 13:58:49 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrBLMWRWlGSWpSXmKPExsXitHSDve5M/ym RBnfXC1ks+biYxYHR4+ju30wBjFGsmXlJ+RUJrBlfu/4yFXzlrrh7YC9jA+M9zi5GTg4JAX+J FWs2soHYbAL6ErtffGICsUUE1CVOd1xkBbGZBfIkOj9+ZAexhQWcJW5MWMzSxcjBwSKgKvGnV QckzCvgKbFk5lw2iJFyEueP/2QGsYUE1CSu9V9ih6gRlDg58wkLxEgJiYMvXjBPYOSehSQ1C0 lqASPTKkaN4tSistQiXUMjvaSizPSMktzEzBxdQwNTvdzU4uLE9NScxKRiveT83E2MwFBgAII djH2znA8xSnIwKYnyBmlNiRTiS8pPqcxILM6ILyrNSS0+xCjDwaEkwTvbDygnWJSanlqRlpkD DEqYtAQHj5IIby9Imre4IDG3ODMdInWKUZfj1YT/35iEWPLy81KlxHkjQYoEQIoySvPgRsAi5 BKjrJQwLyPQUUI8BalFuZklqPKvGMU5GJWEeWeATOHJzCuB2/QK6AgmoCOutE8COaIkESEl1c C4+IdZw5nzHmtCzwi2SLy/yXdW13LHjnnKCnIORZxZMr9u/fRb7iisysBd0CayY2JO1mObLvO YL/teqbUFOxeXKV4+Ja4/efbBYIPE+WeUZCdO2eR187W9rkWp/C3ri61vPq0oEFj0pKzDOOHJ jvcT5K7ErS1888Slzzj22o8fX+O3GLydqayuxFKckWioxVxUnAgAhv5C6YsCAAA= X-Env-Sender: prvs=3941fdc67=Andrew.Cooper3@citrix.com X-Msg-Ref: server-11.tower-206.messagelabs.com!1502891927!86409347!1 X-Originating-IP: [66.165.176.63] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogNjYuMTY1LjE3Ni42MyA9PiAzMDYwNDg=\n, received_headers: No Received headers X-StarScan-Received: X-StarScan-Version: 9.4.45; banners=-,-,- X-VirusChecked: Checked Received: (qmail 21619 invoked from network); 16 Aug 2017 13:58:48 -0000 Received: from smtp02.citrix.com (HELO SMTP02.CITRIX.COM) (66.165.176.63) by server-11.tower-206.messagelabs.com with RC4-SHA encrypted SMTP; 16 Aug 2017 13:58:48 -0000 X-IronPort-AV: E=Sophos;i="5.41,383,1498521600"; d="scan'208";a="444008992" From: Andrew Cooper To: Xen-devel Date: Wed, 16 Aug 2017 14:58:44 +0100 Message-ID: <1502891924-20563-1-git-send-email-andrew.cooper3@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 Cc: Andrew Cooper , Wei Liu , Jan Beulich Subject: [Xen-devel] [PATCH] x86/mm: Reduce debug overhead of __virt_to_maddr() X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP __virt_to_maddr() is used very frequently, but has a large footprint due to its assertions and comparasons. Rearange its logic to drop one assertion entirely, encoding its check in a second assertion (with no additional branch, and the comparason performed with a 32bit immediate rather than requiring a movabs). Bloat-o-meter net report is: add/remove: 0/0 grow/shrink: 1/72 up/down: 3/-2169 (-2166) along with a reduction of 32 assertion frames (895 down to 861) Signed-off-by: Andrew Cooper Reviewed-by: Jan Beulich --- CC: Jan Beulich CC: Wei Liu --- xen/include/asm-x86/x86_64/page.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/xen/include/asm-x86/x86_64/page.h b/xen/include/asm-x86/x86_64/page.h index 947e52b..bd30f25 100644 --- a/xen/include/asm-x86/x86_64/page.h +++ b/xen/include/asm-x86/x86_64/page.h @@ -51,13 +51,15 @@ extern unsigned long xen_virt_end; static inline unsigned long __virt_to_maddr(unsigned long va) { - ASSERT(va >= XEN_VIRT_START); ASSERT(va < DIRECTMAP_VIRT_END); if ( va >= DIRECTMAP_VIRT_START ) va -= DIRECTMAP_VIRT_START; else { - ASSERT(va < XEN_VIRT_END); + BUILD_BUG_ON(XEN_VIRT_END - XEN_VIRT_START != GB(1)); + ASSERT(((long)va >> (PAGE_ORDER_1G + PAGE_SHIFT)) == + ((long)XEN_VIRT_START >> (PAGE_ORDER_1G + PAGE_SHIFT))); + va += xen_phys_start - XEN_VIRT_START; } return (va & ma_va_bottom_mask) |