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[PULL,Xenial,arm64] Increase CONFIG_MAX_ZONEORDER to 13

Message ID CALdTtnud4hAhPmtAfNTzjZ9B1XPMsvOSonS0Lw-qtHjJ8RzzUw@mail.gmail.com
State New
Headers show

Pull-request

git://kernel.ubuntu.com/dannf/ubuntu-xenial.git lp1558828

Message

dann frazier March 21, 2016, 9:57 p.m. UTC 
GICv3 ITS tables need 16MB of contiguous memory
   2^21 devs * 8 bytes per dev = 16MB

However, the default MAX_ZONEORDER setting for arm64 w/ 4K is 11,
which can only provide 4MB of contiguous space. An appropriate
upstream solution is being discussed, but it will likely involve
rearchitecting the ITS driver as a proper device, so that it can make
use of the normal DMA APIs:
  https://lkml.org/lkml/2016/3/1/238

As a no-up workaround, we can bump CONFIG_MAX_ZONEORDER up to 13 to
get the space we need. I've regression tested this on the Dragonboard
410c and found no problems. But, since it uses it's own config, you
might prefer to just disable CONFIG_ARCH_THUNDER in that flavor.

The following changes since commit c3a461f342afc842d56df5dff8cbabd3437ce083:

  arcmsr: change driver version to v1.30.00.22-20151126 (2016-03-21
10:25:17 -0600)

are available in the git repository at:

  git://kernel.ubuntu.com/dannf/ubuntu-xenial.git lp1558828

for you to fetch changes up to c23bf8a43d625848659e74b0caf3ca1458bb37ef:

  UBUNTU: [Config] CONFIG_FORCE_MAX_ZONEORDER=13 on arm64 (2016-03-21
15:35:30 -0600)

----------------------------------------------------------------
Radha Mohan Chintakuntla (1):
      UBUNTU: SAUCE: (no-up) arm64: gicv3: its: Increase
FORCE_MAX_ZONEORDER for Cavium ThunderX

dann frazier (1):
      UBUNTU: [Config] CONFIG_FORCE_MAX_ZONEORDER=13 on arm64

 arch/arm64/Kconfig                             | 1 +
 debian.master/config/arm64/config.common.arm64 | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

Comments

Tim Gardner March 21, 2016, 11:20 p.m. UTC | #1 
I'll have to be careful when rebasing Snapdragon, though it ought not
have any deleterious affect.

rtg