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From: Philippe W. <phi...@sk...> - 2010-09-16 18:55:13
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> From: "Nicholas Nethercote" <n.n...@gm...> > Sent: Tuesday, September 14, 2010 9:04 AM > If you overrun by a very small amount, you'll get a warning. If you > overrun by a slightly larger amount, you may well end up accessing > another heap block, which won't cause a warning. Having a 16 byte > redzone means that more of these small overruns will be caught. Effectively, this reason looks a clear advantage. Wouldn't is be interesting to have the redzone size as a command line option ? That would allow the user to increase the chance to discover nasty bugs by increasing the redzone (or; if user only searches for memleaks, to decrease the memory usage by reducing the redzone). After a quick look at the code, it seems relatively easy to do a patch for that (but I already have two patches waiting for review, so maybe it is not the time to add a 3rd one :). > I think the different arenas have different superblock sizes. Maybe > it's not a good idea, though. Arena superblock size is effectively configured per arena. I do not know how critical it is to reduce the memory usage by valgrind. (i.e. for how many cases a user can't use VG due to too high memory usage. At least at my work, we quite often encounter the limitation (so, my work on bug 250101). If important to reduce the memory footprint of VG, having only one 'non-client' arena is easy to do (even using a command line option). Philippe |