From owner-svn-src-head@freebsd.org Sat Feb 1 19:21:07 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 1DF312288BC; Sat, 1 Feb 2020 19:21:07 +0000 (UTC) (envelope-from lwhsu.freebsd@gmail.com) Received: from mail-yw1-f65.google.com (mail-yw1-f65.google.com [209.85.161.65]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4893pp0W5Pz3Qvk; Sat, 1 Feb 2020 19:21:05 +0000 (UTC) (envelope-from lwhsu.freebsd@gmail.com) Received: by mail-yw1-f65.google.com with SMTP id n184so8773342ywc.3; Sat, 01 Feb 2020 11:21:05 -0800 (PST) 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=R0C+x+YGIUekWTQTKAjJuCjfbokknIkDbzZ5nTsqRF0=; b=JOoEB1EtWC9/H/XLxqXpfq5ye3FjCqetHdZCWDOobOXzfXhMfHuT4+UazPNOaPIXsT 55XpXW/7UwHH7P6aNURtcgxYoCL0XaQHS6FoZXERXZgnDOld9dJJiUFt3MjsNMf0EXaN Ysz7okzNBfOZasYR/j7EpqUE2J+slSdvlZhcntH4fQXGjbh+RqNKhyFVHMPgW03twTit IGukg1uyjnGTFAey9eZvLaeW7CXAb5JXchkVAJeEBlUhvF/0ZHw8/6YLuTzZrWLkSSse 0NON1SkKVrJ33KAkIZ7CR4qduB6f+FplH/I/cy2YWXF5SmZcR+/9PzlPt94JLwOqLbov wPBQ== X-Gm-Message-State: APjAAAWLEK/QJ8vfR+36FKsmemqDFAR52czS9c1EmsDorsdQG6jOaBic GnKQRXIGbdzpy/Y/Ytd56+3wIwPTefTsfUhoYL46Ze+R X-Google-Smtp-Source: APXvYqymqYUpVR3A7XbxndYYfEumTJcBOtw8l42P01lU/y7fS9IXxrDUC9YE2dotUZaMorF7ZWkgQAeZvTtr1xdf1pE= X-Received: by 2002:a0d:c3c2:: with SMTP id f185mr12108354ywd.21.1580584864637; Sat, 01 Feb 2020 11:21:04 -0800 (PST) MIME-Version: 1.0 References: <202001310049.00V0np1a077223@repo.freebsd.org> In-Reply-To: <202001310049.00V0np1a077223@repo.freebsd.org> From: Li-Wen Hsu Date: Sun, 2 Feb 2020 03:20:53 +0800 Message-ID: Subject: Re: svn commit: r357314 - in head/sys: conf kern sys vm To: Jeff Roberson Cc: src-committers , svn-src-all , svn-src-head Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4893pp0W5Pz3Qvk X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of lwhsufreebsd@gmail.com designates 209.85.161.65 as permitted sender) smtp.mailfrom=lwhsufreebsd@gmail.com X-Spamd-Result: default: False [-3.06 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_NEQ_ENVFROM(0.00)[lwhsu@freebsd.org,lwhsufreebsd@gmail.com]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[freebsd.org]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; RWL_MAILSPIKE_GOOD(0.00)[65.161.85.209.rep.mailspike.net : 127.0.0.18]; RCVD_TLS_ALL(0.00)[]; IP_SCORE(-1.06)[ip: (-0.44), ipnet: 209.85.128.0/17(-3.04), asn: 15169(-1.76), country: US(-0.05)]; TO_DN_ALL(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[65.161.85.209.list.dnswl.org : 127.0.5.0]; FORGED_SENDER(0.30)[lwhsu@freebsd.org,lwhsufreebsd@gmail.com]; MIME_TRACE(0.00)[0:+]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; TAGGED_FROM(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 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: Sat, 01 Feb 2020 19:21:07 -0000 On Fri, Jan 31, 2020 at 8:50 AM Jeff Roberson wrote: > > Author: jeff > Date: Fri Jan 31 00:49:51 2020 > New Revision: 357314 > URL: https://svnweb.freebsd.org/changeset/base/357314 > > Log: > Implement a safe memory reclamation feature that is tightly coupled with UMA. > > This is in the same family of algorithms as Epoch/QSBR/RCU/PARSEC but is > a unique algorithm. This has 3x the performance of epoch in a write heavy > workload with less than half of the read side cost. The memory overhead > is significantly lessened by limiting the free-to-use latency. A synthetic > test uses 1/20th of the memory vs Epoch. There is significant further > discussion in the comments and code review. > > This code should be considered experimental. I will write a man page after > it has settled. After further validation the VM will begin using this > feature to permit lockless page lookups. > > Both markj and cperciva tested on arm64 at large core counts to verify > fences on weaker ordering architectures. I will commit a stress testing > tool in a follow-up. > > Reviewed by: mmacy, markj, rlibby, hselasky > Discussed with: sbahara > Differential Revision: https://reviews.freebsd.org/D22586 I found it might cause i386 boot fail: Kernel page fault with the following non-sleepable locks held: exclusive sleep mutex kernel arena (kernel arena) r = 0 (0x1d99d80) locked @ /usr/src/sys/kern/subr_vmem.c:1344 Full backtrace is available at https://ci.freebsd.org/job/FreeBSD-head-i386-test/8275/console Please help checking this. Thanks, Li-Wen