ubuntu-boot team mailing list archive

[Scott James Remnant <scott@xxxxxxxxxxxxx>]

This is a bit of a late performance analysis, since I've been saying how
much better the new modprobe is for a while now, but here's some proper
numbers.

The versions of modprobe I used were the current 3.3 version in jaunty,
the 3.6 release and the GIT HEAD.  All used the same configuration from
the current jaunty package.

First up, average uevent/udev processing times:

        3.3		3.6		GIT
MEAN    2.99s		0.42s		0.38s
MEDIAN  3.32s		0.46s		0.41s
MODE    4.48s		0.71s		0.13s
STDDEV  1.33s		0.21s		0.21s

You may retrieve your hat.

The new modprobe uses binary indexes instead of those large string-based
files.  This makes an unbelievable difference to the average udev
processing time.

There's little difference between 3.6 and the GIT head, which is as
expected - the changes in GIT head are not performance critical.


Boot times:

			3.3	3.6	change		GIT	change		total change
udev in initramfs:	 0.01s	 0.01s	 0     (100%)	 0.01s	 0     (100%)	 0     (100%)
udev in system:		 0.03s	 0.03s	 0     (100%)	 0.03s	 0     (100%)	 0     (100%)

trigger in initramfs:	 0.05s	 0.06s	+0.01s (104%)	 0.06s	 0     (100%)	 0     (100%)
trigger in system:	 0.13s	 0.17s	+0.04s (132%)	 0.13s	-0.04s (75%)	 0     (100%)

processing in initramfs: 0.92s	 0.56s	-0.36s (61%)	 0.56s	 0     (100%)	-0.36s (61%)
processing in system:	 4.88s	 0.79s	-4.09s (16%)	 0.82s  +0.03s (104%)	-4.06s (16%)

time in kernel:		 2.80s	 2.80s	 0     (100%)	 2.81s	+0.01s (100%)	+0.01s (100%)
time in initramfs:	 1.56s	 1.11s	-0.45s (71%)	 1.09s	-0.02s (97%)	-0.47s (69%)
(of which udev)		   65%	   57%			   58%
time booting system	17.97s	12.23s	-5.74s (68%)	12.44s	+0.22s (101%)	-5.52s (69%)
(of which udev)		   28%	    8%			    8%

Again, a massive difference between 3.3 and 3.6, and no significant
difference between 3.6 and GIT head.

Scott
-- 
Scott James Remnant
scott@xxxxxxxxxxxxx

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