| function bitCount(u) { | |
| // https://blogs.msdn.microsoft.com/jeuge/2005/06/08/bit-fiddling-3/ | |
| const uCount = u - ((u >> 1) & 0o33333333333) - ((u >> 2) & 0o11111111111); | |
| return ((uCount + (uCount >> 3)) & 0o30707070707) % 63; | |
| } |
The prep-script.sh will setup the latest Node and install the latest perf version on your Linux box.
When you want to generate the flame graph, run the following (folder locations taken from install script):
sudo sysctl kernel.kptr_restrict=0
# May also have to do the following:
# (additional reading http://unix.stackexchange.com/questions/14227/do-i-need-root-admin-permissions-to-run-userspace-perf-tool-perf-events-ar )
sudo sysctl kernel.perf_event_paranoid=0
In a project I'm working on I ran into the requirement of having some sort of persistent FIFO buffer or pipe in Linux, i.e. something file-like that could accept writes from a process and persist it to disk until a second process reads (and acknowledges) it. The persistence should be both across process restarts as well as OS restarts.
AFAICT unfortunately in the Linux world such a primitive does not exist (named pipes/FIFOs do not persist
Looking for support tables for HTML/CSS/JavaScript features or details on their implementation status in major browsers?
And then there’s Can I use…?.