No subject

[Henry Cejtin]

I  must point out that I think that the signal method of profiling is way way
nicer than having a profil signal call.  The signal call  was  an  incredible
hack  and gave you zero control over what happened on each clock tick.  As an
example, the change I mentioned  of  going  to  4  byte  counters,  would  be
impossible  on  systems where profiling was done in the kernel.  The overhead
is really very very minimal since it only happens 100 times per  second.   It
is  just as accurate as the system call method.  The only real disadvantage I
can see is that it interferes with the state of the program.   For  instance,
if  a  program  blocks  signals some times, then it will also block profiling
counts during those times.  Still, I definitely view it as a real  plus.   It
wouldn't  have  quite  been do-able in the old days since machines were a bit
too slow.

The profiling stuff in the 2.4  kernels  is,  I'm  fairly  certain,  only  to
profile the kernel itself, not any user processes.