From f3612304ee04a1a36ded7604771ea56d818158cb Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 17 Feb 2012 10:29:20 +0100 Subject: [S390] idle: avoid RCU usage in extended quiescent state Avoid calling wake_up() from our NMI "bottom halve" from RCU extended quiescent state in idle. wake_up() has RCU read-side critical sections but this will be completely ignored by RCU if the cpu is in extended quiescent state. Which means that whatever object is being accessed from within the read-side critical section can be freed concurrently from a different cpu. So make sure we leave extended quiescent state before calling wake_up(). Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/process.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/s390/kernel/process.c b/arch/s390/kernel/process.c index 3201ae447990..4261aa799774 100644 --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -76,7 +76,6 @@ static void default_idle(void) if (test_thread_flag(TIF_MCCK_PENDING)) { local_mcck_enable(); local_irq_enable(); - s390_handle_mcck(); return; } trace_hardirqs_on(); @@ -93,10 +92,12 @@ void cpu_idle(void) for (;;) { tick_nohz_idle_enter(); rcu_idle_enter(); - while (!need_resched()) + while (!need_resched() && !test_thread_flag(TIF_MCCK_PENDING)) default_idle(); rcu_idle_exit(); tick_nohz_idle_exit(); + if (test_thread_flag(TIF_MCCK_PENDING)) + s390_handle_mcck(); preempt_enable_no_resched(); schedule(); preempt_disable(); -- cgit v1.2.3 From 2320c5793790fcda80e6dcc088dbda86040235e5 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 17 Feb 2012 10:29:21 +0100 Subject: [S390] incorrect PageTables counter for kvm page tables The page_table_free_pgste function is used for kvm processes to free page tables that have the pgste extension. It calls pgtable_page_ctor instead of pgtable_page_dtor which increases NR_PAGETABLE instead of decreasing it. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/pgtable.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 9a4d02f64f16..51b0738e13d1 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -574,7 +574,7 @@ static inline void page_table_free_pgste(unsigned long *table) page = pfn_to_page(__pa(table) >> PAGE_SHIFT); mp = (struct gmap_pgtable *) page->index; BUG_ON(!list_empty(&mp->mapper)); - pgtable_page_ctor(page); + pgtable_page_dtor(page); atomic_set(&page->_mapcount, -1); kfree(mp); __free_page(page); -- cgit v1.2.3 From cf1eb40f8f5ea12c9e569e7282161fc7f194fd62 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Fri, 17 Feb 2012 10:29:23 +0100 Subject: [S390] correct ktime to tod clock comparator conversion The conversion of the ktime to a value suitable for the clock comparator does not take changes to wall_to_monotonic into account. In fact the conversion just needs the boot clock (sched_clock_base_cc) and the total_sleep_time. This is applicable to 3.2+ kernels. CC: stable@vger.kernel.org Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/time.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c index fa02f443f5f6..14da278febbf 100644 --- a/arch/s390/kernel/time.c +++ b/arch/s390/kernel/time.c @@ -113,11 +113,14 @@ static void fixup_clock_comparator(unsigned long long delta) static int s390_next_ktime(ktime_t expires, struct clock_event_device *evt) { + struct timespec ts; u64 nsecs; - nsecs = ktime_to_ns(ktime_sub(expires, ktime_get_monotonic_offset())); + ts.tv_sec = ts.tv_nsec = 0; + monotonic_to_bootbased(&ts); + nsecs = ktime_to_ns(ktime_add(timespec_to_ktime(ts), expires)); do_div(nsecs, 125); - S390_lowcore.clock_comparator = TOD_UNIX_EPOCH + (nsecs << 9); + S390_lowcore.clock_comparator = sched_clock_base_cc + (nsecs << 9); set_clock_comparator(S390_lowcore.clock_comparator); return 0; } -- cgit v1.2.3