On 2008-09-30, Michael Torrie <[EMAIL PROTECTED]> wrote: >> Just a thought, your minimum sleep time is probably limited by >> the resolution of the system "HZ" clock. Type >> >> less /proc/config.gz >> >> and search for the value of the "CONFIG_HZ" setting. On the >> Athlon 64 machine I'm using to write this, it's 250, which >> should allow for sleep intervals in multiples of 0.004 >> seconds. > > Since most distributions do not create this file in /proc for whatever > reason,
It's also common to put a copy of the config file in /boot (or wherever the kernel binaries are installed). I prefer the /proc/config.gz setup myself, and that's how I configure all my systems. > and some people are being deliberately obtuse, does anyone > know how to ask the kernel what the timer resolution is? Is > it stored anywhere else in /proc or /sys? I kind of think > most distros set it to 1000 Hz, but I'm not sure. We could look in /usr/include: $ grep -r ' HZ ' /usr/include /usr/include/scsi/sg.h:#define SG_DEFAULT_TIMEOUT (60*HZ) /* HZ == 'jiffies in 1 second' */ /usr/include/linux/ixjuser.h:* IXJCTL_HZ sets the value your Linux kernel uses for HZ as defined in /usr/include/linux/n_r3964.h: * Fixed HZ usage on 2.6 kernels /usr/include/asm/param.h:#define HZ 100 But, I happen to know that's wrong and I'm running a kernel with HZ=250. So let's look elsewhere. How about in /proc/sys/kernel? $ cat /proc/sys/kernel/sched_min_granularity_ns 4000000 That looks suspiciously like 1/HZ in nanoseconds. -- Grant -- http://mail.python.org/mailman/listinfo/python-list
