Bug 115371

Summary:	`mmap` does not search for nearby addresses if the requested address is taken
Product:	Memory Management	Reporter:	demetriobenour
Component:	Other	Assignee:	Andrew Morton (akpm)
Status:	NEW ---
Severity:	normal	CC:	thomas.pi
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	3.5	Subsystem:
Regression:	No	Bisected commit-id:

Description demetriobenour 2016-03-28 01:47:58 UTC

According to https://github.com/LuaJIT/LuaJIT/issues/49, if the address passed to mmap(2) is already in use, it is ignored.  This breaks SpiderMonkey and LuaJIT, forcing an ugly workaround (essentially: do the search in userspace), which is racy and slow.

It would be nice to implement the search for a nearby usable address in the kernel.