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=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 82148C433E0 for ; Tue, 9 Feb 2021 01:04:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5966664E99 for ; Tue, 9 Feb 2021 01:04:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229734AbhBIBEV (ORCPT ); Mon, 8 Feb 2021 20:04:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229587AbhBIBEJ (ORCPT ); Mon, 8 Feb 2021 20:04:09 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF8B9C061788 for ; Mon, 8 Feb 2021 17:03:28 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id cv23so603862pjb.5 for ; Mon, 08 Feb 2021 17:03:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:subject:to:cc:references:in-reply-to:mime-version :message-id:content-transfer-encoding; bh=MfcsXfncKqwyZqj9wo90IfUK1Xuq26ciFpVmdsqb4sw=; b=j5O/lJoB6fWuGf5SzkH1gnTYbuONd+VGpxE2jrItYctPzNsUxG8mTGMkmrLluJHy/n y7VeOhTqRYO5GyfJ7ssgtNKjOo7/uBC6kOplsSlMDX+JeVtMRF/6zlpOHy9N8GBkMNad l3DgNqaSbgzNtR2wQm5SgpzzwlTiDAe6KXxAow5huNWk74TB07u75O61RPaef8g5mwZ3 RuazMLkeM9ZaGiRENWKve6/j0E7UCcTiXfpOAtpfed21vZ6xQsgJ6d3aeKS9QBegcIzM 2Tug/R8gr2E/1+Y+ObF77ZS0JXhJFIlLllsIXK7F1c6KqrGXcvKRLGUbeUbMNID9Y12z lwsA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:subject:to:cc:references:in-reply-to :mime-version:message-id:content-transfer-encoding; bh=MfcsXfncKqwyZqj9wo90IfUK1Xuq26ciFpVmdsqb4sw=; b=eXlQypfZdQAnEyWOnhn8jlPDoCiSZUB4QhmiLXmXbYUQUoc1RNZkoo2RWGQGlP+ZXp WIOTipc8v+HiAdt1aBRStlKGpr02kjx9OaQWSJ8lUIIQe7i29GfxnfxLv1/Lhgi4aK5m l1Zjn19MKu2Ru1GKvrvGMGLK3R4cLnRiP3IeMIrXS+dEwDd1u8AmciMGf8a/MBRE+lon K+Ylgi6WBePymMQOJlPH7mz65KOL+OvZ70ff5srMwSR6bdfjgUC0kcni9hYDW9ql4lcH tZfMlFk2klxitK92Z1sK5l8EDohVUGzVmaJYsqoYZBq7Qi8KfzxeutV7m1t/642MR+Vi bhyQ== X-Gm-Message-State: AOAM533UhnQs/0R4DkruauHtx3qcqgoNvxuOsfAyqFASXaW/iZ+a4bRw K3pGsjdktGvosc8hbr48ACGohtGsZQ63/A== X-Google-Smtp-Source: ABdhPJxBFTNVbvcjXcaw2456OCXzobbFg3C8PqR3Wy1L83G9v50cVL32RYMQWVwFOK18iqh+ckrFRg== X-Received: by 2002:a17:90a:da02:: with SMTP id e2mr1438717pjv.173.1612832608592; Mon, 08 Feb 2021 17:03:28 -0800 (PST) Received: from localhost ([220.240.226.199]) by smtp.gmail.com with ESMTPSA id f18sm442920pjq.53.2021.02.08.17.03.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Feb 2021 17:03:27 -0800 (PST) Date: Tue, 09 Feb 2021 11:03:21 +1000 From: Nicholas Piggin Subject: Re: [PATCH v5 00/22] powerpc/32: Implement C syscall entry/exit To: Benjamin Herrenschmidt , Christophe Leroy , Michael Ellerman , msuchanek@suse.de, Paul Mackerras Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org References: In-Reply-To: MIME-Version: 1.0 Message-Id: <1612832388.bbrfxby1h0.astroid@bobo.none> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Excerpts from Christophe Leroy's message of February 9, 2021 1:10 am: > This series implements C syscall entry/exit for PPC32. It reuses > the work already done for PPC64. >=20 > This series is based on today's merge-test (b6f72fc05389e3fc694bf5a5fa1bb= d33f61879e0) >=20 > In terms on performance we have the following number of cycles on an > 8xx running null_syscall benchmark: > - mainline: 296 cycles > - after patch 4: 283 cycles > - after patch 16: 304 cycles > - after patch 17: 348 cycles > - at the end of the series: 320 cycles >=20 > So in summary, we have a degradation of performance of 8% on null_syscall= . >=20 > I think it is not a big degradation, it is worth it. I guess it's 13% from 283. But it's very nice to use the shared C code. There might be a few more percent speedup in there we can find later. Thanks, Nick