Ian Holsman wrote:
On 05 Jul 2001 22:59:25 +0100, David Reid wrote:
OK, to comment on this prior to the patch being posted...
I have SMS running as pools and the implementation I have manages to run the server at 80% of the speed of pools. This is with no changes to the httpd code except using --enable-sms on the configure line. Now, this isn't amazing, but does present a starting point. As I said we haven't started optimising or altering.
[...]
If you post your patch, I'll run it through quantify which should highlight where the bottlenecks are.
Detailed profile data from Quantify would be extremely useful--not just for the new SMS-based pools, but also for APR and the httpd in general.
This morning, I instrumented the latest httpd-2.0 souce and found that it's spending 41% of its CPU time in usr mode and 59% in sys when delivering a 50KB, non-server-parsed file (on Linux, using sendfile). For server-parsed requests, I've seen ratios as high as 70% usr, 30% sys.
The bad news: the httpd is wasting a huge amount of CPU time in user-space code (for an optimal httpd serving static files, the usr CPU should approach zero; 41% is surprisingly high). The good news: there's an opportunity to cut the httpd's CPU utilization nearly in half by tuning just the user-space code.
--Brian
