Various CPU usage gains from profiling #742

tomwilkie · 2015-12-10T11:36:27Z

Buildings on #741. ~~Will rebase when #737 is merged.~~

Fixes #284. Saves another 1-2% CPU on my VM, down to about 7.5% CPU usage for the probe.

Use Readdirnames to reduce number of stat systcalls we're doing.
Cache the contents of some files in /proc that aren't expected to change.
Don't decode the certificates everytime we create an AppClient.
Don't read tcp6 file (we don't deal with ipv6 anywhere else).

probe/endpoint/procspy/proc.go

+		if err != nil {
+			// Process is be gone by now, or we don't have access.
+			return
+		}


Also cache contents of /proc/foo/stat, but only for 10s.

Various CPU usage gains from profiling

tomwilkie force-pushed the 284-profiling branch from 20e42e0 to 51c21ea Compare December 10, 2015 14:29

Use Readdirnames to reduce number of stats we're doing.

1fcd079

tomwilkie force-pushed the 284-profiling branch from 51c21ea to 419f523 Compare December 10, 2015 14:43

paulbellamy reviewed Dec 10, 2015
View reviewed changes

probe/endpoint/procspy/proc.go

if err != nil {

// Process is be gone by now, or we don't have access.

return

}

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tomwilkie added 4 commits December 11, 2015 10:27

Cache the contents of some files in /proc

cde5920

Also cache contents of /proc/foo/stat, but only for 10s.

Don't decode the certificates everytime we create an AppClient.

9cff569

Don't read tcp6 file (we don't deal with ipv6 anywhere else).

cc90c6c

Don't list fds if there are not connections in the net namespace.

a2862ba

tomwilkie force-pushed the 284-profiling branch from dbe010c to a2862ba Compare December 11, 2015 10:33

paulbellamy added a commit that referenced this pull request Dec 11, 2015

Merge pull request #742 from weaveworks/284-profiling

1b39659

Various CPU usage gains from profiling

paulbellamy merged commit 1b39659 into master Dec 11, 2015

paulbellamy deleted the 284-profiling branch December 11, 2015 12:05

tomwilkie mentioned this pull request Dec 15, 2015

We need to read /proc/PID/net/tcp6 to see the pids for the server end of local connections. #770

Merged

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Various CPU usage gains from profiling #742

Various CPU usage gains from profiling #742

tomwilkie commented Dec 10, 2015

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Various CPU usage gains from profiling #742

Various CPU usage gains from profiling #742

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tomwilkie commented Dec 10, 2015

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