Messages in this thread | | | Subject | Re: [PATCHv4 2/5] x86/mm: introduce mmap{,_legacy}_base | From | Dmitry Safonov <> | Date | Mon, 13 Feb 2017 17:37:09 +0300 |
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On 02/11/2017 05:13 PM, Thomas Gleixner wrote: >> -static unsigned long mmap_base(unsigned long rnd) >> +static unsigned long mmap_base(unsigned long rnd, unsigned long task_size) >> { >> unsigned long gap = rlimit(RLIMIT_STACK); > unsigned long gap_min, gap_max; > > /* Add comment what this means */ > gap_min = SIZE_128M + stack_maxrandom_size(task_size); > /* Explain that ' /6 * 5' magic */ > gap_max = (task_size / 6) * 5;
So, I can't find about those limits on a gap size: They were introduced by commit 8913d55b6c58 ("i386 virtual memory layout rework"). All I could find is that 128Mb limit was more limit on virtual adress space than on a memory available those days. And 5/6 of task_size looks like heuristic value. So I'm not sure, what to write in comments: that rlimit on stack can't be bigger than 5/6 of task_size? That looks obvious from the code.
-- Dmitry
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