Date: Sat, 15 Nov 2008 06:16:31 -0800 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: Won De Erick <won.derick@yahoo.com> Cc: freebsd-hackers@freebsd.org, rwatson@freebsd.org Subject: Re: NET.ISR and CPU utilization performance w/ HP DL 585 using FreeBSD 7.1 Beta2 Message-ID: <20081115141631.GA75733@icarus.home.lan> In-Reply-To: <557765.55617.qm@web45804.mail.sp1.yahoo.com> References: <557765.55617.qm@web45804.mail.sp1.yahoo.com>
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On Sat, Nov 15, 2008 at 04:59:16AM -0800, Won De Erick wrote: > Hello, > > I tested HP DL 585 (16 CPUs, w/ built-in Broadcom NICs) running FreeBSD 7.1 Beta2 under heavy network traffic (TCP). > > SCENARIO A : Bombarded w/ TCP traffic: > > When net.isr.direct=1, > > PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND > 52 root 1 -68 - 0K 16K CPU11 b 38:43 95.36% irq32: bce1 > 51 root 1 -68 - 0K 16K CPU10 a 25:50 85.16% irq31: bce0 > 16 root 1 171 ki31 0K 16K RUN a 65:39 15.97% idle: cpu10 > 28 root 1 -32 - 0K 16K WAIT 8 12:28 5.18% swi4: clock sio > 15 root 1 171 ki31 0K 16K RUN b 52:46 3.76% idle: cpu11 > 45 root 1 -64 - 0K 16K WAIT 7 7:29 1.17% irq17: uhci0 > 47 root 1 -64 - 0K 16K WAIT 6 1:11 0.10% irq16: ciss0 > 27 root 1 -44 - 0K 16K WAIT 0 28:52 0.00% swi1: net > > When net.isr.direct=0, > > 16 root 1 171 ki31 0K 16K CPU10 a 106:46 92.58% idle: cpu10 > 19 root 1 171 ki31 0K 16K CPU7 7 133:37 89.16% idle: cpu7 > 27 root 1 -44 - 0K 16K WAIT 0 52:20 76.37% swi1: net > 25 root 1 171 ki31 0K 16K RUN 1 132:30 70.26% idle: cpu1 > 26 root 1 171 ki31 0K 16K CPU0 0 111:58 64.36% idle: cpu0 > 15 root 1 171 ki31 0K 16K CPU11 b 81:09 57.76% idle: cpu11 > 52 root 1 -68 - 0K 16K WAIT b 64:00 42.97% irq32: bce1 > 51 root 1 -68 - 0K 16K WAIT a 38:22 12.26% irq31: bce0 > 45 root 1 -64 - 0K 16K WAIT 7 11:31 12.06% irq17: uhci0 > 47 root 1 -64 - 0K 16K WAIT 6 1:54 3.66% irq16: ciss0 > 28 root 1 -32 - 0K 16K WAIT 8 16:01 0.00% swi4: clock sio > > Overall CPU utilization has significantly dropped, but I noticed that swi1 has taken CPU0 with high utilization when the net.isr.direct=0. > What does this mean? > > SCENARIO B : Bombarded w/ more TCP traffic: > > Worst thing, the box has become unresponsive (can't be PINGed, inaccessible through SSH) after more traffic was added retaining net.isr.direct=0. > This is due maybe to the 100% utilization on CPU0 for sw1:net (see below result, first line). bce's and swi's seem to race each other based on the result when net.isr.direct=1, swi1 . > The rest of the CPUs are sitting pretty (100% Idle). Can you shed some lights on this? > > When net.isr.direct=0: > 27 root 1 -44 - 0K 16K CPU0 0 5:45 100.00% swi1: net > 11 root 1 171 ki31 0K 16K CPU15 0 0:00 100.00% idle: cpu15 > 13 root 1 171 ki31 0K 16K CPU13 0 0:00 100.00% idle: cpu13 > 17 root 1 171 ki31 0K 16K CPU9 0 0:00 100.00% idle: cpu9 > 18 root 1 171 ki31 0K 16K CPU8 0 0:00 100.00% idle: cpu8 > 21 root 1 171 ki31 0K 16K CPU5 5 146:17 99.17% idle: cpu5 > 22 root 1 171 ki31 0K 16K CPU4 4 146:17 99.07% idle: cpu4 > 14 root 1 171 ki31 0K 16K CPU12 0 0:00 99.07% idle: cpu12 > 16 root 1 171 ki31 0K 16K CPU10 a 109:33 98.88% idle: cpu10 > 15 root 1 171 ki31 0K 16K CPU11 b 86:36 93.55% idle: cpu11 > 52 root 1 -68 - 0K 16K WAIT b 59:42 13.87% irq32: bce1 > > When net.isr.direct=1, > 52 root 1 -68 - 0K 16K CPU11 b 55:04 97.66% irq32: bce1 > 51 root 1 -68 - 0K 16K CPU10 a 33:52 73.88% irq31: bce0 > 16 root 1 171 ki31 0K 16K RUN a 102:42 26.86% idle: cpu10 > 15 root 1 171 ki31 0K 16K RUN b 81:20 3.17% idle: cpu11 > 28 root 1 -32 - 0K 16K WAIT e 13:40 0.00% swi4: clock sio > > With regards to bandwidth in all scenarios above, the result is extremely low (expected is several hundred Mb/s). Why? > > - iface Rx Tx Total > ============================================================================== > bce0: 4.69 Mb/s 10.49 Mb/s 15.18 Mb/s > bce1: 20.66 Mb/s 4.68 Mb/s 25.34 Mb/s > lo0: 0.00 b/s 0.00 b/s 0.00 b/s > ------------------------------------------------------------------------------ > total: 25.35 Mb/s 15.17 Mb/s 40.52 Mb/s > > > Thanks, > > Won And does this behaviour change if you use some other brand of NIC? -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
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