stm class: Use vmalloc for the master map
authorAlexander Shishkin <alexander.shishkin@linux.intel.com>
Thu, 24 May 2018 08:27:26 +0000 (11:27 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 25 May 2018 16:09:16 +0000 (18:09 +0200)
commitb5e2ced9bf81393034072dd4d372f6b430bc1f0a
tree8488697f70e5d0df849898cccd6e51359bbfd59e
parentdd010bd7af6248b40ab31640a6e31fbebea5aa22
stm class: Use vmalloc for the master map

Fengguang is running into a warning from the buddy allocator:

> swapper/0: page allocation failure: order:9, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null)
> CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.17.0-rc1 #262
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
> Call Trace:
...
>  __kmalloc+0x14b/0x180: ____cache_alloc at mm/slab.c:3127
>  stm_register_device+0xf3/0x5c0: stm_register_device at drivers/hwtracing/stm/core.c:695
...

Which is basically a result of the stm class trying to allocate ~512kB
for the dummy_stm with its default parameters. There's no reason, however,
for it not to be vmalloc()ed instead, which is what this patch does.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hwtracing/stm/core.c