Re: lowlatency 2.2.19

[William Montgomery]

On Mon, 4 Jun 2001, Andrea Arcangeli wrote:

> On Sun, Jun 03, 2001 at 10:38:34AM -0400, William Montgomery wrote:
> > Anyone have any ideas?  
> 
> Which options did you enabled? In theory the ikd patch could only make
> the latency worse ;), there are no performance improvements in it but
> only runtime debugging stuff.
> 
I am including a snippet from my .config:
#
# Kernel hacking
#
CONFIG_MAGIC_SYSRQ=y
# CONFIG_KMSGDUMP is not set
CONFIG_KERNEL_DEBUGGING=y
# CONFIG_SEMAPHORE_DEADLOCK is not set
# CONFIG_DEBUG_KSTACK is not set
# CONFIG_KSTACK_METER is not set
# CONFIG_DEBUG_SOFTLOCKUP is not set
# CONFIG_PROFILE_GCC is not set
CONFIG_TRACE=y
CONFIG_TRACE_SIZE=16384
CONFIG_TRACE_TIMESTAMP=y
# CONFIG_TRACE_TRUNCTIME is not set
CONFIG_TRACE_PID=y
CONFIG_TRACE_CPU=y
CONFIG_DEBUG_MCOUNT=y
# CONFIG_PRINT_EIP is not set
# CONFIG_MEMLEAK is not set
# CONFIG_KDB is not set

-------
I cant see anything that could make latency better either but
I can induce 1 to 2.5msec jitter in a 2.2.19 kernel with only 
lowlatency patch after a few minutes stress testing.  

The kernel with both ikd and lowlatency patches tests fine
after 24 hrs of stress testing - jitter always under 1msec.

Wm