Re: [linux-usb-devel] USB performance bug since kernel 2.6.13 (CRITICAL???)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Sat, 14 Oct 2006, Alan Cox wrote:

> Ar Gwe, 2006-10-13 am 16:30 -0700, ysgrifennodd Open Source:
> > There is an ioctl that is waiting for the URB to be reaped.
> > I am almost certain it is this syscall that is taking 4 ms (as
> > opposed to 1 ms with CONFIG_HZ=1000).
> 
> What does strace say about it ? This is measurable not speculation.

I completely agree with the other Alan.  You don't have to guess about
these things.  Use strace to see what your process is doing and at the
same time use usbmon to see what the USB stack is doing.  Run the 
experiment at both 1000 Hz and 250 Hz and compare the results.

Alan Stern

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux