]> git.baikalelectronics.ru Git - kernel.git/commit
memory-hotplug: use dev_online for memhp_auto_online
authorNathan Fontenot <nfont@linux.vnet.ibm.com>
Fri, 24 Feb 2017 23:00:02 +0000 (15:00 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 25 Feb 2017 01:46:56 +0000 (17:46 -0800)
commit37492adbb3140dbcbf22d6ed2f816afce0a932e4
treec72bb090e93017548b6f50537883e151caf87ac4
parentdfcdbb9599b1381a056e2e8b81d8e08a597b7121
memory-hotplug: use dev_online for memhp_auto_online

Commit 91a3a9846aa0 ("add automatic onlining policy for the newly added
memory") provides the capability to have added memory automatically
onlined during add, but this appears to be slightly broken.

The current implementation uses walk_memory_range() to call
online_memory_block, which uses memory_block_change_state() to online
the memory.  Instead, we should be calling device_online() for the
memory block in online_memory_block().  This would online the memory
(the memory bus online routine memory_subsys_online() called from
device_online calls memory_block_change_state()) and properly update the
device struct offline flag.

As a result of the current implementation, attempting to remove a memory
block after adding it using auto online fails.  This is because doing a
remove, for instance

  echo offline > /sys/devices/system/memory/memoryXXX/state

uses device_offline() which checks the dev->offline flag.

Link: http://lkml.kernel.org/r/20170222220744.8119.19687.stgit@ltcalpine2-lp14.aus.stglabs.ibm.com
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/base/memory.c
include/linux/memory.h
mm/memory_hotplug.c