From: Krzysztof Witkowski <Krzysztof.Witkowski@mobile.put.edu.pl>
To: Wolfgang Grandegger <wg@grandegger.com>
Cc: linux-can@vger.kernel.org
Subject: Re: CPU load inhibits CAN interrupts
Date: Wed, 11 Apr 2012 11:40:31 +0200 [thread overview]
Message-ID: <4F85518F.9020305@mobile.put.edu.pl> (raw)
In-Reply-To: <4F847253.5080507@grandegger.com>
W dniu 4/10/2012 7:48 PM, Wolfgang Grandegger pisze:
>> However, if I generate artificial CPU load with stress command:
>>
>> chrt --idle 0 stress -c 2
>
> What does "-c 2" do? My "chrt" command does not have that option.
It is an option for stress command:
-c, --cpu N
spawn N workers spinning on sqrt()
>> Why CPU load inhibits hardware interrupts and what can be done about it?
>
> Hm, what does "ip -d -s can0" report while you are producing CPU load
> with the stress command above.
# ip -s -d link show can0
4: can0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UNKNOWN
mode DEFAULT qlen 10
link/can
can state ERROR-PASSIVE (berr-counter tx 0 rx 128) restart-ms 100
bitrate 1000000 sample-point 0.750
tq 125 prop-seg 2 phase-seg1 3 phase-seg2 2 sjw 2
sja1000: tseg1 1..16 tseg2 1..8 sjw 1..4 brp 1..64 brp-inc 1
clock 8000000
re-started bus-errors arbit-lost error-warn error-pass bus-off
0 0 0 1 1 0
RX: bytes packets errors dropped overrun mcast
728 91 0 0 0 0
TX: bytes packets errors dropped carrier collsns
0 0 0 0 0 0
It can occasionally deliver packets, but the rate is no more than ~2
packets/second.
next prev parent reply other threads:[~2012-04-11 11:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-10 14:40 CPU load inhibits CAN interrupts Krzysztof Witkowski
2012-04-10 17:48 ` Wolfgang Grandegger
2012-04-11 9:40 ` Krzysztof Witkowski [this message]
2012-04-11 13:23 ` Wolfgang Grandegger
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F85518F.9020305@mobile.put.edu.pl \
--to=krzysztof.witkowski@mobile.put.edu.pl \
--cc=linux-can@vger.kernel.org \
--cc=wg@grandegger.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.