From owner-svn-src-head@freebsd.org Wed Jun 6 19:03:57 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 2A491FDF00E; Wed, 6 Jun 2018 19:03:57 +0000 (UTC) (envelope-from pho@holm.cc) Received: from relay01.pair.com (relay01.pair.com [209.68.5.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D146A82A77; Wed, 6 Jun 2018 19:03:56 +0000 (UTC) (envelope-from pho@holm.cc) Received: from x2.osted.lan (87-58-223-204-dynamic.dk.customer.tdc.net [87.58.223.204]) by relay01.pair.com (Postfix) with ESMTP id 5D874D010C3; Wed, 6 Jun 2018 15:03:55 -0400 (EDT) Received: from x2.osted.lan (localhost [127.0.0.1]) by x2.osted.lan (8.15.2/8.15.2) with ESMTPS id w56J3rfs080913 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 6 Jun 2018 21:03:53 +0200 (CEST) (envelope-from pho@x2.osted.lan) Received: (from pho@localhost) by x2.osted.lan (8.15.2/8.15.2/Submit) id w56J3ro6080912; Wed, 6 Jun 2018 21:03:53 +0200 (CEST) (envelope-from pho) Date: Wed, 6 Jun 2018 21:03:53 +0200 From: Peter Holm To: Matt Macy Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r333744 - in head/sys: kern sys Message-ID: <20180606190353.GA80061@x2.osted.lan> References: <201805171759.w4HHxZpe069821@repo.freebsd.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201805171759.w4HHxZpe069821@repo.freebsd.org> User-Agent: Mutt/1.10.0 (2018-05-17) 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: Wed, 06 Jun 2018 19:03:57 -0000 On Thu, May 17, 2018 at 05:59:35PM +0000, Matt Macy wrote: > Author: mmacy > Date: Thu May 17 17:59:35 2018 > New Revision: 333744 > URL: https://svnweb.freebsd.org/changeset/base/333744 > > Log: > AF_UNIX: make unix socket locking finer grained > > This change moves to using a reference count across lock drop / reacquire > to guarantee liveness. > > Currently sends on unix sockets contend heavily on read locking the list lock. > unix1_processes in will-it-scale peaks at 6 processes and then declines. > > With this change I get a substantial improvement in number of operations per second > with 96 processes: > > x before > + after > N Min Max Median Avg Stddev > x 11 1688420 1696389 1693578 1692766.3 2971.1702 > + 10 63417955 71030114 70662504 69576423 2374684.6 > Difference at 95.0% confidence > 6.78837e+07 +/- 1.49463e+06 > 4010.22% +/- 88.4246% > (Student's t, pooled s = 1.63437e+06) > > And even for 2 processes shows a ~18% improvement. > "Small" iron changes (1, 2, and 4 processes): > > x before1 > + after1.2 > +------------------------------------------------------------------------+ > | + | > | x + | > | x + | > | x + | > | x ++ | > | xx ++ | > |x x xx ++ | > | |__________________A_____M_____AM____|| > +------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 10 1131648 1197750 1197138.5 1190369.3 20651.839 > + 10 1203840 1205056 1204919 1204827.9 353.27404 > Difference at 95.0% confidence > 14458.6 +/- 13723 > 1.21463% +/- 1.16683% > (Student's t, pooled s = 14605.2) > > x before2 > + after2.2 > +------------------------------------------------------------------------+ > | +| > | +| > | +| > | +| > | +| > | +| > | x +| > | x +| > | x xx +| > |x xxxx +| > | |___AM_| A| > +------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 10 1972843 2045866 2038186.5 2030443.8 21367.694 > + 10 2400853 2402196 2401043.5 2401172.7 385.40024 > Difference at 95.0% confidence > 370729 +/- 14198.9 > 18.2585% +/- 0.826943% > (Student's t, pooled s = 15111.7) > > x before4 > + after4.2 > N Min Max Median Avg Stddev > x 10 3986994 3991728 3990137.5 3989985.2 1300.0164 > + 10 4799990 4806664 4806116.5 4805194 1990.6625 > Difference at 95.0% confidence > 815209 +/- 1579.64 > 20.4314% +/- 0.0421713% > (Student's t, pooled s = 1681.19) > > Tested by: pho > Reported by: mjg > Approved by: sbruno > Sponsored by: Limelight Networks > Differential Revision: https://reviews.freebsd.org/D15430 > > Modified: > head/sys/kern/uipc_usrreq.c > head/sys/sys/unpcb.h > > Modified: head/sys/kern/uipc_usrreq.c > ============================================================================== > --- head/sys/kern/uipc_usrreq.c Thu May 17 17:57:41 2018 (r333743) This commit seems to cause this: 20180606 20:44:37 all (1/1): datagram.sh panic: _mtx_lock_sleep: recursed on non-recursive mutex unp_mtx @ ../../../kern/uipc_usrreq.c:354 cpuid = 91 time = 1528310678 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00f3a2bcd0 vpanic() at vpanic+0x1a3/frame 0xfffffe00f3a2bd30 doadump() at doadump/frame 0xfffffe00f3a2bdb0 __mtx_lock_sleep() at __mtx_lock_sleep+0x49d/frame 0xfffffe00f3a2be30 __mtx_lock_flags() at __mtx_lock_flags+0xf9/frame 0xfffffe00f3a2be80 unp_connectat() at unp_connectat+0x2ec/frame 0xfffffe00f3a2c110 soconnectat() at soconnectat+0xe8/frame 0xfffffe00f3a2c160 kern_connectat() at kern_connectat+0x10f/frame 0xfffffe00f3a2c1c0 sys_connect() at sys_connect+0x77/frame 0xfffffe00f3a2c200 amd64_syscall() at amd64_syscall+0x2a7/frame 0xfffffe00f3a2c330 fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00f3a2c330 --- syscall (98, FreeBSD ELF64, sys_connect), rip = 0x80040081a, rsp = 0x7fffffffe2e8, rbp = 0x7fffffffe770 --- KDB: enter: panic [ thread pid 1276 tid 100966 ] Stopped at kdb_enter+0x3b: movq $0,kdb_why db> x/s version version: FreeBSD 12.0-CURRENT #0 r333744: Wed Jun 6 20:35:18 CEST 2018\012 pho@flix1a.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO\012 db> The stack trace is different on HEAD: panic: mutex unp not owned at ../../../kern/uipc_usrreq.c:879 cpuid = 47 time = 1528311629 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00ee593ca0 vpanic() at vpanic+0x1a3/frame 0xfffffe00ee593d00 panic() at panic+0x43/frame 0xfffffe00ee593d60 __mtx_assert() at __mtx_assert+0xb4/frame 0xfffffe00ee593d70 uipc_disconnect() at uipc_disconnect+0x93/frame 0xfffffe00ee593dc0 soclose() at soclose+0xa5/frame 0xfffffe00ee593e30 closef() at closef+0x1f5/frame 0xfffffe00ee593ec0 fdescfree_fds() at fdescfree_fds+0x90/frame 0xfffffe00ee593f10 fdescfree() at fdescfree+0x480/frame 0xfffffe00ee593fd0 exit1() at exit1+0x500/frame 0xfffffe00ee594040 sigexit() at sigexit+0xae8/frame 0xfffffe00ee594220 postsig() at postsig+0x1cf/frame 0xfffffe00ee5942f0 ast() at ast+0x4b8/frame 0xfffffe00ee594330 doreti_ast() at doreti_ast+0x1f/frame 0x7fffffffe760 KDB: enter: panic [ thread pid 1013 tid 100834 ] Stopped at kdb_enter+0x3b: movq $0,kdb_why db> x/s version version: FreeBSD 12.0-CURRENT #0 r334723: Wed Jun 6 20:53:32 CEST 2018\012 pho@flix1a.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO\012 db> - Peter