arm: mm: let CONFIG_VMALLOC_SAVING increase vmalloc by default
By current definition, CONFIG_VMALLOC_SAVING uses the VA space of
carveout areas as vmalloc area, but reduces the size of default
vmalloc space, thereby keeping the total vmalloc size same as
without CONFIG_VMALLOC_SAVING, and in turn increasing the lowmem.
This means, changes in carveout sizes will have the side effect
of altering the vmalloc size, which will then need "vmalloc"
kernel param changes for every change in carveout size. And these
changes in values passed to vmalloc kernel param, can have a side
effect on targets that shares the kernel params but does not save
any VA space using CONFIG_VMALLOC_SAVING (for e.g. when some or
all of the carveouts are in highmem area.).
It can be argued that this patch changes the meaning of vmalloc
kernel param, and is bad. For e.g. when vmalloc=300M is passed,
the user may expect the vmalloc to be 300M, but the actual total
vmalloc will be 300M plus VA recovered from carveouts. This won't
seem to be an issue if "vmalloc" param is understood as a method
to increase the "default" vmalloc area size.
Change-Id: I30bc22f1c685a7de92ca331bf32ca152798fc13b
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
1 file changed