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Re: [PATCH] kprobes for s390 architecture
- From: Mike Grundy <grundym at us dot ibm dot com>
- To: Heiko Carstens <heiko dot carstens at de dot ibm dot com>
- Cc: Martin Schwidefsky <schwidefsky at de dot ibm dot com>, Jan Glauber <jan dot glauber at de dot ibm dot com>, linux-kernel at vger dot kernel dot org, systemtap at sources dot redhat dot com
- Date: Tue, 11 Jul 2006 09:54:30 -0400
- Subject: Re: [PATCH] kprobes for s390 architecture
- References: <20060623150344.GL9446@osiris.boeblingen.de.ibm.com> <OF44DB398C.F7A51098-ON88257196.007CD277-88257196.007DC8F0@us.ibm.com> <20060623222106.GA25410@osiris.ibm.com> <20060624113641.GB10403@osiris.ibm.com> <1151421789.5390.65.camel@localhost> <20060628055857.GA9452@osiris.boeblingen.de.ibm.com> <20060707172333.GA12068@localhost.localdomain> <20060707172555.GA10452@osiris.ibm.com>
On Fri, Jul 07, 2006 at 07:25:55PM +0200, Heiko Carstens wrote:
> > ok, I tried, but my "better ideas" made things worse. stop_machine_run() wins:
> How fast is this if you have to exchange several hundred instructions?
I did a little measuring. On average stop_machine_run() adds 8.7 msec of
overhead on a 4-way config. Of that %57 was sub-msec overhead. For the times
where overhead was measurable, the average was 20.2 msec, lowest at 10msec
highest at 100msec. That's on a z800 under vm and I have no idea how many real
cpus the machine has :-)
Michael Grundy - firstname.lastname@example.org
Advanced Linux Response Team (ALRT)
845-435-8842 (T/L 295)
If at first you don't succeed, call in an air strike.