From owner-freebsd-virtualization@freebsd.org Tue Feb 28 19:46:21 2017 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 19976CF1D3C for ; Tue, 28 Feb 2017 19:46:21 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (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 F26A78D for ; Tue, 28 Feb 2017 19:46:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id v1SJkKjR053539 for ; Tue, 28 Feb 2017 19:46:20 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-virtualization@FreeBSD.org Subject: [Bug 216759] [kern] Memory speed with small blocks (1K) up to 35 times slower than host system (under QEMU emulation, but not only) Date: Tue, 28 Feb 2017 19:46:21 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 11.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: andrew@azar-a.net X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-virtualization@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 28 Feb 2017 19:46:21 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D216759 --- Comment #11 from andrew@azar-a.net --- Here are the latest results supporting my previous post: root@debian8-test:~# sysbench --num-threads=3D1 --test=3Dmemory --memory-total-size=3D512M --memory-block-size=3D1K --debug run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Debug mode enabled. Doing memory operations speed test Memory block size: 1K Memory transfer size: 512M Memory operations type: write Memory scope type: global Threads started! DEBUG: Runner thread started (0)! Done. Operations performed: 524288 (3877252.90 ops/sec) 512.00 MB transferred (3786.38 MB/sec) Test execution summary: total time: 0.1352s total number of events: 524288 total time taken by event execution: 0.1093 per-request statistics: min: 0.00ms avg: 0.00ms max: 0.14ms approx. 95 percentile: 0.00ms Threads fairness: events (avg/stddev): 524288.0000/0.00 execution time (avg/stddev): 0.1093/0.00 DEBUG: Verbose per-thread statistics: DEBUG: thread # 0: min: 0.0000s avg: 0.0000s max: 0.0001s events: 524288 DEBUG: total time taken by even execution: 0.1093s root@debian8-test:~# cat /sys/bus/clocksource/devices/clocksource0/current_clocksource tsc root@debian8-test:~# cat /sys/bus/clocksource/devices/clocksource0/available_clocksource tsc hpet acpi_pm root@dev:~ # dmesg | grep -i "TSC" Calibrating TSC clock ... TSC clock: 3400129027 Hz =20 Features=3D0xf83fbff =20 Features2=3D0xfffa3203 AMD Features=3D0x2c100800 TSC timecounter discards lower 1 bit(s) Timecounter "TSC-low" frequency 1700064513 Hz quality -100 root@dev:~ # sysbench --num-threads=3D1 --test=3Dmemory --memory-total-size= =3D512M --memory-block-size=3D1K --debug run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Debug mode enabled. Doing memory operations speed test Memory block size: 1K Memory transfer size: 512M Memory operations type: write Memory scope type: global Threads started! DEBUG: Runner thread started (0)! Done. Operations performed: 524288 (73267.52 ops/sec) 512.00 MB transferred (71.55 MB/sec) Test execution summary: total time: 7.1558s total number of events: 524288 total time taken by event execution: 5.2780 per-request statistics: min: 0.01ms avg: 0.01ms max: 0.72ms approx. 95 percentile: 0.00ms Threads fairness: events (avg/stddev): 524288.0000/0.00 execution time (avg/stddev): 5.2780/0.00 DEBUG: Verbose per-thread statistics: DEBUG: thread # 0: min: 0.0000s avg: 0.0000s max: 0.0007s events: 524288 DEBUG: total time taken by even execution: 5.2780s root@dev:~ # sysctl kern.timecounter.hardware=3DTSC-low kern.timecounter.hardware: HPET -> TSC-low root@dev:~ # sysbench --num-threads=3D1 --test=3Dmemory --memory-total-size= =3D512M --memory-block-size=3D1K --debug run sysbench 0.4.12: multi-threaded system evaluation benchmark Running the test with following options: Number of threads: 1 Debug mode enabled. Doing memory operations speed test Memory block size: 1K Memory transfer size: 512M Memory operations type: write Memory scope type: global Threads started! DEBUG: Runner thread started (0)! Done. Operations performed: 524288 (3408336.84 ops/sec) 512.00 MB transferred (3328.45 MB/sec) Test execution summary: total time: 0.1538s total number of events: 524288 total time taken by event execution: 0.1102 per-request statistics: min: 0.00ms avg: 0.00ms max: 0.24ms approx. 95 percentile: 0.00ms Threads fairness: events (avg/stddev): 524288.0000/0.00 execution time (avg/stddev): 0.1102/0.00 DEBUG: Verbose per-thread statistics: DEBUG: thread # 0: min: 0.0000s avg: 0.0000s max: 0.0002s events: 524288 DEBUG: total time taken by even execution: 0.1102s So it's even worse than memory lag - it's gettimeofday() function lag, basically all software relies on it one way or another.... --=20 You are receiving this mail because: You are the assignee for the bug.=