Messages in this thread | | | Date | Sun, 11 May 2008 05:08:43 -0700 | From | John Reiser <> | Subject | Re: [ANNOUNCE] kmemcheck v7 |
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Vegard Nossum wrote: > How is the speed of Valgrind+UML, does anybody know?
The speed of Valgrind+UML is the same as the speed of valgrind on any application. On a 2GHz box it took about 2.5 minutes to reach "login:" from a cold boot of UML (includes udev, etc.) So if normal boot takes 15 seconds, then that's a factor of 10 slowdown: slow for interactivity, yet bearable for checking. The memory-intensive portions (linear search, pointer chasing, etc.) can be slower still, but loops that concentrate on register arithmetic or conditional branching go faster. There is almost no system wait time: normal device delays (disk, network) get totally overlapped by CPU usage for grinding :-)
I'd like to have both kmemcheck and valgrind+UML, and use them differently. Run kmemcheck all the time on a box or two as "background trolling" for infrequent cases. Use valgrind+UML for interactivity and programmable flexibility when hunting specific bugs, or when hardware cannot be dedicated.
-- John Reiser, jreiser@BitWagon.com
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