From owner-svn-src-head@freebsd.org Thu May 24 01:19:10 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 75821EF0568 for ; Thu, 24 May 2018 01:19:10 +0000 (UTC) (envelope-from lists@eitanadler.com) Received: from mail-yb0-x236.google.com (mail-yb0-x236.google.com [IPv6:2607:f8b0:4002:c09::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E80B069307 for ; Thu, 24 May 2018 01:19:09 +0000 (UTC) (envelope-from lists@eitanadler.com) Received: by mail-yb0-x236.google.com with SMTP id l2-v6so7065651ybp.8 for ; Wed, 23 May 2018 18:19:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=eitanadler.com; s=0xdeadbeef; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=sJgWBvpgBYbU6Y26kofbFHtbCZfcWIwLh7KGlSZv7zU=; b=rImOWWq+/h79dFPQHxEFryhWUIrHLLKJR8OWZzHiNwO7RZ0eWJrlM0baNqneCJHcem vzm0IKG2sdIKDdkeacn2IdE7nwFW4u+GRqBo3g4fPDo4cS3Gw8o57tR1iF6YV3qvNdCu tr8c88WTOdJDmcyi3O1850Tv8CwBgNP2h15UQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=sJgWBvpgBYbU6Y26kofbFHtbCZfcWIwLh7KGlSZv7zU=; b=Q1iEhC4rC30fza1ecN+jC9XK43HBhy/04q2+00qFx/vNfkdyGBEViZK49tRnovH0/3 jRQOCB0uHFKxNX7lD7ixdN40jH5re4o5rqS3XsWtLEL9Tav1dzjMA/j/SI3LGdfsQfR7 73K3fXRm9Uydls4cxLZdYVQKD6XQcd+BHxEyfwQAYojTpQROvVBIixGaQkjqWwiZKsyH bdKIgFvUkKe4dIldajPJO210cuX8c1SWoqyTqrhxUvFD7ixQHBSa44KJQJqbHs0FENmi LIPe6OSI8xSZ0JyBGTXGRLBPNK85LCRuytSPTq8K6qsGwftJm2jylcAg/FXZfTBN3e4O VUjw== X-Gm-Message-State: ALKqPwdGzpi9mEcEyo5LF6alQU69SSj7A+wRQwqiaeFhXjU1XCc8vtdA XeFlSA3jCfqyMGM8gkh9qEFNVScncbioWNElqqRjXw== X-Google-Smtp-Source: AB8JxZq4MFSiGpEUIBqPLZwoEFH6FK65zfCcn/GVecdknLSQX23v3v1Mo4EptWad+pUzq2JGET+bEfUr1aUtWYyVzPw= X-Received: by 2002:a25:2605:: with SMTP id m5-v6mr3008944ybm.89.1527124749369; Wed, 23 May 2018 18:19:09 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a25:c709:0:0:0:0:0 with HTTP; Wed, 23 May 2018 18:18:38 -0700 (PDT) In-Reply-To: References: <201805231700.w4NH05hs047395@repo.freebsd.org> <2281830.zrSQodBeDb@ralph.baldwin.cx> From: Eitan Adler Date: Wed, 23 May 2018 18:18:38 -0700 Message-ID: Subject: Re: svn commit: r334104 - in head/sys: netinet sys To: "Jonathan T. Looney" Cc: Matthew Macy , John Baldwin , src-committers , svn-src-all@freebsd.org, svn-src-head@freebsd.org Content-Type: text/plain; charset="UTF-8" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 May 2018 01:19:10 -0000 On 23 May 2018 at 17:40, Jonathan T. Looney wrote: > On Wed, May 23, 2018 at 7:13 PM, Matthew Macy wrote: >> >> On Wed, May 23, 2018 at 11:52 AM, John Baldwin wrote: >> > On Wednesday, May 23, 2018 05:00:05 PM Matt Macy wrote: >> >> Author: mmacy >> >> Date: Wed May 23 17:00:05 2018 >> >> New Revision: 334104 >> >> URL: https://svnweb.freebsd.org/changeset/base/334104 >> >> >> >> Log: >> >> epoch: allow for conditionally asserting that the epoch context >> >> fields >> >> are unused by zeroing on INVARIANTS builds >> > >> > Is M_ZERO really so bad that you need to make it conditional? >> >> In this case not at all. It's only exercised by sysctl handlers. I'm >> mostly responding to an inquiry by jtl. However, gratuitous M_ZERO >> usage does have a cumulative adverse performance impact. > > I appreciate you making this change. And, I do think it is worth avoiding > M_ZERO where it is unnecessary, for the reason you state. > >> > I would probably have preferred something like 'M_ZERO_INVARIANTS' >> > instead perhaps (or M_ZERO_EPOCH) that only controls M_ZERO and is >> > still or'd with M_WAITOK or M_NOWAIT. >> >> Yes. I like that better too. Thanks. > > Yes, that does seem better. +1 to M_ZERO_INVARIANTS -- Eitan Adler