Search found 3 matches

by sadface
Sun Nov 22, 2009 3:46 am
Forum: Support
Topic: getPeerCandidates() remake
Replies: 2
Views: 2557

new patch!

Hi,

Forget my last patch, please . It degrades seeding performance.

This new one does reduce cpu usage on both download and upload stages.
Changes:

peerIsInUse() was moved to the lastest place of filtering chain. Thus we avoid calling this expensive function mainly on seeding stage.
As the ...
by sadface
Fri Nov 20, 2009 6:39 pm
Forum: Support
Topic: getPeerCandidates() remake
Replies: 2
Views: 2557

getPeerCandidates() remake

Hi!

OProfile helped me (again) to find out that calling peerIsInUse() for each atom is expensive. But as maxCandidates value is previously known, we can sort atoms first and filter only a small subset of them later.

Despite sorting time and memory requirements are lightly increased, this patch ...
by sadface
Thu Nov 19, 2009 12:09 am
Forum: Support
Topic: Too much system cpu usage
Replies: 2
Views: 2707

Too much system cpu usage

I noticed that symptom on my x86 linux machine running transmission-daemon.

OProfile and strace tools showed me the guilty: thousands of time() syscalls per second combined with a "slow" kernel high-resolution timer (ACPI PM timer). In these conditions every time() syscall wastes from 5 to 6 usecs ...