Charm triggered thousands of reads to /etc/localtime on my machine
every few seconds, leading to periodic disk sleeps. Profiling
with strace -k and perf trace showed the culprits: Lots and lots
of QDateTime usage in the local time zone. The real hotspots can
easily be converted to use UTC instead, minimizing the required
conversions and thus the load on the hard disk.
Before, I easily ended up with ~18k reads to /etc/localtime every
5 seconds or so. Now, this value is down to less than 200.
Charm triggered thousands of reads to /etc/localtime on my machine every few seconds, leading to periodic disk sleeps. Profiling with strace -k and perf trace showed the culprits: Lots and lots of QDateTime usage in the local time zone. The real hotspots can easily be converted to use UTC instead, minimizing the required conversions and thus the load on the hard disk.
Before, I easily ended up with ~18k reads to /etc/localtime every 5 seconds or so. Now, this value is down to less than 200.