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| author | Michal Hocko <mhocko@suse.com> | 2017-11-15 17:33:38 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:02 -0800 |
| commit | ecde0f3e7f9edf8629f56b2354385dc8d0a6a24d (patch) | |
| tree | 5f82d86166ffc872db9c43ecc1da30f138fcd723 | |
| parent | 72b39cfc4d750e5b8c633a7a6fdd7d07927995ad (diff) | |
| download | linux-stable-ecde0f3e7f9edf8629f56b2354385dc8d0a6a24d.tar.gz linux-stable-ecde0f3e7f9edf8629f56b2354385dc8d0a6a24d.tar.bz2 linux-stable-ecde0f3e7f9edf8629f56b2354385dc8d0a6a24d.zip | |
mm, memory_hotplug: remove timeout from __offline_memory
We have a hardcoded 120s timeout after which the memory offline fails
basically since the hot remove has been introduced. This is essentially
a policy implemented in the kernel. Moreover there is no way to adjust
the timeout and so we are sometimes facing memory offline failures if
the system is under a heavy memory pressure or very intensive CPU
workload on large machines.
It is not very clear what purpose the timeout actually serves. The
offline operation is interruptible by a signal so if userspace wants
some timeout based termination this can be done trivially by sending a
signal.
If there is a strong usecase to do this from the kernel then we should
do it properly and have a it tunable from the userspace with the timeout
disabled by default along with the explanation who uses it and for what
purporse.
Link: http://lkml.kernel.org/r/20170918070834.13083-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | mm/memory_hotplug.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 014e9090cb77..fab51a6af962 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1590,9 +1590,9 @@ static void node_states_clear_node(int node, struct memory_notify *arg) } static int __ref __offline_pages(unsigned long start_pfn, - unsigned long end_pfn, unsigned long timeout) + unsigned long end_pfn) { - unsigned long pfn, nr_pages, expire; + unsigned long pfn, nr_pages; long offlined_pages; int ret, node; unsigned long flags; @@ -1630,12 +1630,8 @@ static int __ref __offline_pages(unsigned long start_pfn, goto failed_removal; pfn = start_pfn; - expire = jiffies + timeout; repeat: /* start memory hot removal */ - ret = -EBUSY; - if (time_after(jiffies, expire)) - goto failed_removal; ret = -EINTR; if (signal_pending(current)) goto failed_removal; @@ -1708,7 +1704,7 @@ failed_removal: /* Must be protected by mem_hotplug_begin() or a device_lock */ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) { - return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); + return __offline_pages(start_pfn, start_pfn + nr_pages); } #endif /* CONFIG_MEMORY_HOTREMOVE */ |