Re: [PATCH v6] add MAP_UNLOCKED mmap flag

[KOSAKI Motohiro]

> Hi Gleb,
> 
> On Tue, Jan 19, 2010 at 10:26 AM, Gleb Natapov <gleb@xxxxxxxxxx> wrote:
> >> design would still be broken, no? Did you try using (or extending)
> >> posix_madvise(MADV_DONTNEED) for the guest address space? It seems to
> > After mlockall() I can't even allocate guest address space. Or do you mean
> > instead of mlockall()? Then how MADV_DONTNEED will help? It just drops
> > page table for the address range (which is not what I need) and does not
> > have any long time effect.
> 
> Oh right, MADV_DONTNEED is no good.

Off topic:

posix_madvise(MADV_DONTNEED) is nop. glibc's posix_madvise(MADV_DONTNEED)
don't call linux's madvise(MADV_DONTNEED).
It's because madvise(MADV_DONTNEED) is not POSIX compliant. 

The behavior of linux madvise(MADV_DONTNEED) is similar to Solaris (or *BSD) 
madvise(MADV_FREE).




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