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authorHeiko Carstens <heiko.carstens@de.ibm.com>2011-05-23 10:24:34 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2011-05-23 10:24:29 +0200
commitf2db2e6cb3f5f766cbb3788af44705685ff2445a (patch)
tree11fbf5522f332e13f9bfb6cf4552513e4d865003 /arch/s390/kernel
parentb456d94a9757db54eca4677c1b3a13e7170c9bb3 (diff)
downloadop-kernel-dev-f2db2e6cb3f5f766cbb3788af44705685ff2445a.zip
op-kernel-dev-f2db2e6cb3f5f766cbb3788af44705685ff2445a.tar.gz
[S390] pfault: cpu hotplug vs missing completion interrupts
On cpu hot remove a PFAULT CANCEL command is sent to the hypervisor which in turn will cancel all outstanding pfault requests that have been issued on that cpu (the same happens with a SIGP cpu reset). The result is that we end up with uninterruptible processes where the interrupt that would wake up these processes never arrives. In order to solve this all processes which wait for a pfault completion interrupt get woken up after a cpu hot remove. The worst case that could happen is that they fault again and in turn need to wait again. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel')
-rw-r--r--arch/s390/kernel/asm-offsets.c1
-rw-r--r--arch/s390/kernel/entry.S1
-rw-r--r--arch/s390/kernel/entry64.S1
3 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index ef45556..edfbd17 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -124,6 +124,7 @@ int main(void)
DEFINE(__LC_LAST_UPDATE_TIMER, offsetof(struct _lowcore, last_update_timer));
DEFINE(__LC_LAST_UPDATE_CLOCK, offsetof(struct _lowcore, last_update_clock));
DEFINE(__LC_CURRENT, offsetof(struct _lowcore, current_task));
+ DEFINE(__LC_CURRENT_PID, offsetof(struct _lowcore, current_pid));
DEFINE(__LC_THREAD_INFO, offsetof(struct _lowcore, thread_info));
DEFINE(__LC_KERNEL_STACK, offsetof(struct _lowcore, kernel_stack));
DEFINE(__LC_ASYNC_STACK, offsetof(struct _lowcore, async_stack));
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 1b67fc6..0476174 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -212,6 +212,7 @@ __switch_to:
lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
lm %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
st %r3,__LC_CURRENT # store task struct of next
+ mvc __LC_CURRENT_PID(4,%r0),__TASK_pid(%r3) # store pid of next
st %r5,__LC_THREAD_INFO # store thread info of next
ahi %r5,STACK_SIZE # end of kernel stack of next
st %r5,__LC_KERNEL_STACK # store end of kernel stack
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 9fd8645..d61967e 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -220,6 +220,7 @@ __switch_to:
lctl %c4,%c4,__TASK_pid(%r3) # load pid to control reg. 4
lmg %r6,%r15,__SF_GPRS(%r15) # load gprs of next task
stg %r3,__LC_CURRENT # store task struct of next
+ mvc __LC_CURRENT_PID+4(4,%r0),__TASK_pid(%r3) # store pid of next
stg %r5,__LC_THREAD_INFO # store thread info of next
aghi %r5,STACK_SIZE # end of kernel stack of next
stg %r5,__LC_KERNEL_STACK # store end of kernel stack
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