* Verifying module
@ 2011-01-03 13:06 Mag Gam
2011-01-03 20:06 ` Mulyadi Santosa
0 siblings, 1 reply; 4+ messages in thread
From: Mag Gam @ 2011-01-03 13:06 UTC (permalink / raw)
To: kernelnewbies
We are planning to deploy a system for a client. I was told that
leaving unnecessary modules (ie. jfs, usb, etc...) will not cause
latencies in the kernel however the client is very sensitive. They
care about latencies in microseconds and I was wondering if leaving
unnecessary modules loaded would cause it and how can I measure the
kernel latency (with lmbench if possible) w/o necessary modules.
TIA
^ permalink raw reply [flat|nested] 4+ messages in thread
* Verifying module
2011-01-03 13:06 Verifying module Mag Gam
@ 2011-01-03 20:06 ` Mulyadi Santosa
2011-01-04 3:15 ` Mag Gam
0 siblings, 1 reply; 4+ messages in thread
From: Mulyadi Santosa @ 2011-01-03 20:06 UTC (permalink / raw)
To: kernelnewbies
Hi...
On Mon, Jan 3, 2011 at 20:06, Mag Gam <magawake@gmail.com> wrote:
> We are planning to deploy a system for a client. I was told that
> leaving unnecessary modules (ie. jfs, usb, etc...) will not cause
> latencies in the kernel however the client is very sensitive.
That is right...module is only loaded as needed..
>They
> care about latencies in microseconds and I was wondering if leaving
> unnecessary modules loaded would cause it
if you just "leave" them, it wouldn't add any overhead IMHO. Only if
it is loaded. For that, you could either blacklist them or
better....deselect them during kernel config. Whichever suits you
better
PS: If you're really sensitive, perhaps you could make all of your
modules build into the kernel image...therefore there won't be any
modules. But beware, the kernel image will be damn big :)
>and how can I measure the
> kernel latency (with lmbench if possible) w/o necessary modules.
what latency are we talking here? scheduling latency?
--
regards,
Mulyadi Santosa
Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
^ permalink raw reply [flat|nested] 4+ messages in thread
* Verifying module
2011-01-03 20:06 ` Mulyadi Santosa
@ 2011-01-04 3:15 ` Mag Gam
2011-01-04 5:03 ` Mulyadi Santosa
0 siblings, 1 reply; 4+ messages in thread
From: Mag Gam @ 2011-01-04 3:15 UTC (permalink / raw)
To: kernelnewbies
I am talking about scheduling latency and more important network latency
On Mon, Jan 3, 2011 at 3:06 PM, Mulyadi Santosa
<mulyadi.santosa@gmail.com> wrote:
> Hi...
>
> On Mon, Jan 3, 2011 at 20:06, Mag Gam <magawake@gmail.com> wrote:
>> We are planning to deploy a system for a client. I was told that
>> leaving unnecessary modules (ie. jfs, usb, etc...) will not cause
>> latencies in the kernel however the client is very sensitive.
>
> That is right...module is only loaded as needed..
>
>>They
>> care about latencies in microseconds and I was wondering if leaving
>> unnecessary modules loaded would cause it
>
> if you just "leave" them, it wouldn't add any overhead IMHO. Only if
> it is loaded. For that, you could either blacklist them or
> better....deselect them during kernel config. Whichever suits you
> better
>
> PS: If you're really sensitive, perhaps you could make all of your
> modules build into the kernel image...therefore there won't be any
> modules. But beware, the kernel image will be damn big :)
>
>>and how can I measure the
>> kernel latency (with lmbench if possible) w/o necessary modules.
>
> what latency are we talking here? scheduling latency?
>
> --
> regards,
>
> Mulyadi Santosa
> Freelance Linux trainer and consultant
>
> blog: the-hydra.blogspot.com
> training: mulyaditraining.blogspot.com
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Verifying module
2011-01-04 3:15 ` Mag Gam
@ 2011-01-04 5:03 ` Mulyadi Santosa
0 siblings, 0 replies; 4+ messages in thread
From: Mulyadi Santosa @ 2011-01-04 5:03 UTC (permalink / raw)
To: kernelnewbies
Hi..
On Tue, Jan 4, 2011 at 10:15, Mag Gam <magawake@gmail.com> wrote:
> I am talking about scheduling latency and more important ?network latency
Please don't do top posting....
About measuring latency, I think you can use lmbench along with ftrace
(check http://lxr.linux.no/linux+*/Documentation/trace/events.txt for
the details). Uhm and I think you could probably use the new "perf"
tool, which is bundled in vanilla kernel tarball.
Network latency? Perhaps you can check this article "Benchmarking
network performance with Network Pipemeter, LMbench, and nuttcp"
(http://www.linux.com/archive/feature/144532)
All in all, the things that might affect the latency stuffs IMHO are:
all tracing related functionality, traffic filtering/shaping, security
modules. even if they were indeed loaded, I think the overhead might
be negligible if you use them carefully and properly.
--
regards,
Mulyadi Santosa
Freelance Linux trainer and consultant
blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-01-04 5:03 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-01-03 13:06 Verifying module Mag Gam
2011-01-03 20:06 ` Mulyadi Santosa
2011-01-04 3:15 ` Mag Gam
2011-01-04 5:03 ` Mulyadi Santosa
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).