Re: [PATCHv4 2/5] x86/mm: introduce mmap{,_legacy}_base

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>



[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]
  Powered by Linux