Subject: Re: Flag MAP_NORESERVE for mmap() implemented in NetBSD 3.0?
To: Christian Biere <firstname.lastname@example.org>
From: SODA Noriyuki <email@example.com>
Date: 11/15/2006 19:46:34
>>>>> On Wed, 15 Nov 2006 11:01:31 +0100,
Christian Biere <firstname.lastname@example.org> said:
>> Now any clues whether NetBSD does overcommit during memory allocations like
>> Linux does?
> I don't think it does.
Well, the following behavior is called "overcommitting".
i.e. NetBSD (and all Mach derived VMs) does overcommit for now.
> At least, I can mmap() 1 GiB with MAP_ANON|MAP_PRIVATE
> without having that much RAM and swap being disabled. The program crashes
> during memset() then. With swap enabled it doesn't crash. So there's no
> guarantee that the mapped memory is actually accesible or available.
See also kern/12451