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| author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2011-05-23 10:24:34 +0200 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2011-05-23 10:24:29 +0200 |
| commit | f2db2e6cb3f5f766cbb3788af44705685ff2445a (patch) | |
| tree | 11fbf5522f332e13f9bfb6cf4552513e4d865003 /arch/s390/kernel/entry.S | |
| parent | [S390] smp: add __noreturn attribute to cpu_die() (diff) | |
| download | linux-f2db2e6cb3f5f766cbb3788af44705685ff2445a.tar.xz linux-f2db2e6cb3f5f766cbb3788af44705685ff2445a.zip | |
[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/entry.S')
| -rw-r--r-- | arch/s390/kernel/entry.S | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 1b67fc6ebdc2..0476174dfff5 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 |