Re: [PATCH v1 2/5] drivers/base/memory: map MMOP_OFFLINE to 0
From: Michal Hocko <mhocko@kernel.org>
Date: 2020-03-16 15:19:32
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linux-hyperv, linux-mm, lkml
On Wed 11-03-20 13:30:23, David Hildenbrand wrote:
I have no idea why we have to start at -1.
Because this is how the offline state offline was represented originally.
Just treat 0 as the special case. Clarify a comment (which was wrong, when we come via device_online() the first time, the online_type would have been 0 / MEM_ONLINE). The default is now always MMOP_OFFLINE.
git grep says that you have covered the only remaining place which hasn't used the enum value.
This is a preparation to use the online_type as an array index. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Wei Yang <redacted> Signed-off-by: David Hildenbrand <redacted>
Acked-by: Michal Hocko <mhocko@suse.com>
quoted hunk ↗ jump to hunk
--- drivers/base/memory.c | 11 ++++------- include/linux/memory_hotplug.h | 2 +- 2 files changed, 5 insertions(+), 8 deletions(-)diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 8c5ce42c0fc3..e7e77cafef80 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c@@ -211,17 +211,14 @@ static int memory_subsys_online(struct device *dev) return 0; /* - * If we are called from state_store(), online_type will be - * set >= 0 Otherwise we were called from the device online - * attribute and need to set the online_type. + * When called via device_online() without configuring the online_type, + * we want to default to MMOP_ONLINE. */ - if (mem->online_type < 0) + if (mem->online_type == MMOP_OFFLINE) mem->online_type = MMOP_ONLINE; ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); - - /* clear online_type */ - mem->online_type = -1; + mem->online_type = MMOP_OFFLINE; return ret; }diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 261dbf010d5d..c2e06ed5e0e9 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h@@ -48,7 +48,7 @@ enum { /* Types for control the zone type of onlined and offlined memory */ enum { /* Offline the memory. */ - MMOP_OFFLINE = -1, + MMOP_OFFLINE = 0, /* Online the memory. Zone depends, see default_zone_for_pfn(). */ MMOP_ONLINE, /* Online the memory to ZONE_NORMAL. */-- 2.24.1
-- Michal Hocko SUSE Labs