Add suspend-related notifications for CPU hotplug

Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2 insertions, 2 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index 4317c1be4d3f..8301e2ac747f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3450,7 +3450,7 @@ static int dev_cpu_callback(struct notifier_block *nfb,
         unsigned int cpu, oldcpu = (unsigned long)ocpu;
         struct softnet_data *sd, *oldsd;
 
-        if (action != CPU_DEAD)
+        if (action != CPU_DEAD && action != CPU_DEAD_FROZEN)
                 return NOTIFY_OK;
 
         local_irq_disable();
diff --git a/net/core/flow.c b/net/core/flow.c
index 5d25697920b1..051430545a05 100644
--- a/net/core/flow.c
+++ b/net/core/flow.c
@@ -338,7 +338,7 @@ static int flow_cache_cpu(struct notifier_block *nfb,
                           unsigned long action,
                           void *hcpu)
 {
-        if (action == CPU_DEAD)
+        if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
                 __flow_cache_shrink((unsigned long)hcpu, 0);
         return NOTIFY_OK;
 }