Hello,

On May 9, 2005, at 1:31 PM, Pete French wrote:

5.3 ships with SMP turned on, which makes lock operations rather
expensive on single-processor machines.  4.x does not have SMP
turned on by default.  Would you be able to re-run your test with
SMP turned off?


I just ran a test here with SMP turned of on 5.4-RC4 (GENERIC) I got the
following result:


       67.52 real        41.13 user        26.16 sys
      7034  involuntary context switches

i.e. it still has system time a a huge proportion of the total compared
to the 4.11 kernel. Interesingly, after reading Holger Kipp's results
I tried it on a genuine multi-processor box with SMP enabled running 5.3.
He got a very small percentage of the time in sys (3.51 out of 81.90) but
I got:
255.30 real 160.20 user 88.50 sys


Once again a far higher proprtion of the time spent in sys than you would
expect.

I ran ktrace(1) on it, and it appears that python keeps calling sigprocmask() continually:


   673 python   0.000007 CALL  sigprocmask(0x3,0,0x811d11c)
   673 python   0.000005 RET   sigprocmask 0
   673 python   0.000009 CALL  sigprocmask(0x1,0,0x8113d1c)
   673 python   0.000005 RET   sigprocmask 0
etc..

This explains why it's using so much system time. Now the question is why is python doing this?

--
Suleiman Souhlal     | [EMAIL PROTECTED]
The FreeBSD Project  | [EMAIL PROTECTED]

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