PCI latency

PCI latency

[Giuliano Pochini]

The documentation of my card says I should set pci latency to 0xC0. What
is that latency ?  How do I change it ?


Bye.




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Re: PCI latency

[Jan "Evil Twin" Depner]

I've got some documentation on that on my web page -
http://myweb.cableone.net/eviltwin69/ALSA_JACK_ARDOUR.html.

0xC0 is 192 decimal.  You can go up to 248.

Jan


On Fri, 2003-03-28 at 17:08, Giuliano Pochini wrote:
> 
> The documentation of my card says I should set pci latency to 0xC0. What
> is that latency ?  How do I change it ?
> 
> 
> Bye.
> 
> 
> 
> 
> -------------------------------------------------------
> This SF.net email is sponsored by:
> The Definitive IT and Networking Event. Be There!
> NetWorld+Interop Las Vegas 2003 -- Register today!
> http://ads.sourceforge.net/cgi-bin/redirect.pl?keyn0001en
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/alsa-devel




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PCI: latency

[Subhashini Rao Beerisetty]

 [ Please keep me in CC as I'm not subscribed to the list]

Hi all,

We are using the Linux OS on an x86_64 machine. I need to measure the
PCIe latency on my system, does kernel have any latency measurement
module for the PCIe bus?

Thanks,

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PCI: latency

[Subhashini Rao Beerisetty]

 [ Please keep me in CC as I'm not subscribed to the list]

Hi all,

We are using the Linux OS on an x86_64 machine. I need to measure the
PCIe latency on my system, does kernel have any latency measurement
module for the PCIe bus?

Thanks,

Re: PCI: latency

[Greg KH]

On Fri, Dec 03, 2021 at 10:30:58PM +0530, Subhashini Rao Beerisetty wrote:
>  [ Please keep me in CC as I'm not subscribed to the list]
> 
> Hi all,
> 
> We are using the Linux OS on an x86_64 machine. I need to measure the
> PCIe latency on my system, does kernel have any latency measurement
> module for the PCIe bus?

How exactly are you going to define PCIe latency?

And what is this going to be used for?

thanks,

greg k-h

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Re: PCI: latency

[Greg KH]

On Fri, Dec 03, 2021 at 10:30:58PM +0530, Subhashini Rao Beerisetty wrote:
>  [ Please keep me in CC as I'm not subscribed to the list]
> 
> Hi all,
> 
> We are using the Linux OS on an x86_64 machine. I need to measure the
> PCIe latency on my system, does kernel have any latency measurement
> module for the PCIe bus?

How exactly are you going to define PCIe latency?

And what is this going to be used for?

thanks,

greg k-h

Re: PCI: latency

[Bjorn Helgaas]

On Fri, Dec 03, 2021 at 10:30:58PM +0530, Subhashini Rao Beerisetty wrote:
>  [ Please keep me in CC as I'm not subscribed to the list]
> 
> Hi all,
> 
> We are using the Linux OS on an x86_64 machine. I need to measure the
> PCIe latency on my system, does kernel have any latency measurement
> module for the PCIe bus?

No, unfortunately not.  Maybe perf could help, but I don't know enough
to give you any pointers.

There are a couple tune/trace things like [1], but they're specific to
hardware that you're probably not using.

[1] https://lore.kernel.org/r/20211116090625.53702-1-yangyicong@hisilicon.com

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Re: PCI: latency

[Bjorn Helgaas]

On Fri, Dec 03, 2021 at 10:30:58PM +0530, Subhashini Rao Beerisetty wrote:
>  [ Please keep me in CC as I'm not subscribed to the list]
> 
> Hi all,
> 
> We are using the Linux OS on an x86_64 machine. I need to measure the
> PCIe latency on my system, does kernel have any latency measurement
> module for the PCIe bus?

No, unfortunately not.  Maybe perf could help, but I don't know enough
to give you any pointers.

There are a couple tune/trace things like [1], but they're specific to
hardware that you're probably not using.

[1] https://lore.kernel.org/r/20211116090625.53702-1-yangyicong@hisilicon.com