On 06 Aug 2001 14:05:52 +0100, Alan Cox wrote:
> > Yes, that's what's happening above. And it's what's causing the
> > splits in the vmas. So basically evolution-mail is doing exactly what
> > your test program was doing, and causing exactly the same thing.
> >
> > Seems strange that glibc would do this unless there was some performance
> > reason on past kernels to do it?
>
> Are you sure thats not evolution being built with a debugging malloc of
> some kind ?
Yes, as per cw's e-mail it's just how malloc() works in some cases on
glibc. Allocate 2 * sz (where sz is a relatively large amount compared
to the amount being malloc()'d), free up the 'sz' which is not aligned
to a multiple of 'sz', and the gradually mprotect(PROT_READ|PROT_WRITE)
the memory it's allocated initially with PROT_NONE and MAP_NORESERVE.
And mprotect() responds by splitting up the vmas and never merging them
back together.
-- David Luyer Phone: +61 3 9674 7525 Engineering Projects Manager P A C I F I C Fax: +61 3 9699 8693 Pacific Internet (Australia) I N T E R N E T Mobile: +61 4 1111 2983 http://www.pacific.net.au/ NASDAQ: PCNTF - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Tue Aug 07 2001 - 21:00:42 EST