From: Ingo Molnar <mingo@elte.hu>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: [git pull] core kernel fixes
Date: Sat, 31 Jan 2009 00:12:58 +0100 [thread overview]
Message-ID: <20090130231258.GA11961@elte.hu> (raw)
Linus,
Please pull the latest core-fixes-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git core-fixes-for-linus
Thanks,
Ingo
------------------>
Ed Swierk (1):
signals, debug: fix BUG: using smp_processor_id() in preemptible code in print_fatal_signal()
Rusty Russell (1):
cpumask: convert lib/smp_processor_id to new cpumask ops
Steven Rostedt (1):
generic-ipi: use per cpu data for single cpu ipi calls
kernel/signal.c | 2 ++
kernel/smp.c | 36 +++++++++++++++++++++++++++++++++---
lib/smp_processor_id.c | 2 +-
3 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/kernel/signal.c b/kernel/signal.c
index e737597..b6b3676 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -909,7 +909,9 @@ static void print_fatal_signal(struct pt_regs *regs, int signr)
}
#endif
printk("\n");
+ preempt_disable();
show_regs(regs);
+ preempt_enable();
}
static int __init setup_print_fatal_signals(char *str)
diff --git a/kernel/smp.c b/kernel/smp.c
index 5cfa0e5..bbedbb7 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -18,6 +18,7 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_function_lock);
enum {
CSD_FLAG_WAIT = 0x01,
CSD_FLAG_ALLOC = 0x02,
+ CSD_FLAG_LOCK = 0x04,
};
struct call_function_data {
@@ -186,6 +187,9 @@ void generic_smp_call_function_single_interrupt(void)
if (data_flags & CSD_FLAG_WAIT) {
smp_wmb();
data->flags &= ~CSD_FLAG_WAIT;
+ } else if (data_flags & CSD_FLAG_LOCK) {
+ smp_wmb();
+ data->flags &= ~CSD_FLAG_LOCK;
} else if (data_flags & CSD_FLAG_ALLOC)
kfree(data);
}
@@ -196,6 +200,8 @@ void generic_smp_call_function_single_interrupt(void)
}
}
+static DEFINE_PER_CPU(struct call_single_data, csd_data);
+
/*
* smp_call_function_single - Run a function on a specific CPU
* @func: The function to run. This must be fast and non-blocking.
@@ -224,14 +230,38 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
func(info);
local_irq_restore(flags);
} else if ((unsigned)cpu < nr_cpu_ids && cpu_online(cpu)) {
- struct call_single_data *data = NULL;
+ struct call_single_data *data;
if (!wait) {
+ /*
+ * We are calling a function on a single CPU
+ * and we are not going to wait for it to finish.
+ * We first try to allocate the data, but if we
+ * fail, we fall back to use a per cpu data to pass
+ * the information to that CPU. Since all callers
+ * of this code will use the same data, we must
+ * synchronize the callers to prevent a new caller
+ * from corrupting the data before the callee
+ * can access it.
+ *
+ * The CSD_FLAG_LOCK is used to let us know when
+ * the IPI handler is done with the data.
+ * The first caller will set it, and the callee
+ * will clear it. The next caller must wait for
+ * it to clear before we set it again. This
+ * will make sure the callee is done with the
+ * data before a new caller will use it.
+ */
data = kmalloc(sizeof(*data), GFP_ATOMIC);
if (data)
data->flags = CSD_FLAG_ALLOC;
- }
- if (!data) {
+ else {
+ data = &per_cpu(csd_data, me);
+ while (data->flags & CSD_FLAG_LOCK)
+ cpu_relax();
+ data->flags = CSD_FLAG_LOCK;
+ }
+ } else {
data = &d;
data->flags = CSD_FLAG_WAIT;
}
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
index 0f8fc22..4689cb0 100644
--- a/lib/smp_processor_id.c
+++ b/lib/smp_processor_id.c
@@ -22,7 +22,7 @@ notrace unsigned int debug_smp_processor_id(void)
* Kernel threads bound to a single CPU can safely use
* smp_processor_id():
*/
- if (cpus_equal(current->cpus_allowed, cpumask_of_cpu(this_cpu)))
+ if (cpumask_equal(¤t->cpus_allowed, cpumask_of(this_cpu)))
goto out;
/*
next reply other threads:[~2009-01-30 23:13 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-30 23:12 Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-01-29 11:53 [GIT PULL] core kernel fixes Ingo Molnar
2020-01-29 19:10 ` pr-tracker-bot
2019-05-18 8:51 Ingo Molnar
2019-05-19 17:45 ` pr-tracker-bot
2019-05-16 15:51 Ingo Molnar
2019-05-16 18:20 ` pr-tracker-bot
2018-07-21 11:58 Ingo Molnar
2017-12-06 22:01 Ingo Molnar
2017-11-05 14:33 Ingo Molnar
2017-11-05 18:09 ` Linus Torvalds
2017-11-05 19:53 ` Josh Poimboeuf
2017-11-05 20:12 ` Linus Torvalds
2017-11-05 21:01 ` Josh Poimboeuf
2017-07-21 10:01 Ingo Molnar
2016-10-18 10:14 Ingo Molnar
2016-07-13 10:55 Ingo Molnar
2016-04-03 10:45 Ingo Molnar
2015-02-06 18:28 Ingo Molnar
2012-10-23 10:57 Ingo Molnar
2012-08-03 16:31 Ingo Molnar
2012-08-03 16:55 ` Darren Hart
2012-08-03 17:01 ` Ingo Molnar
2012-08-03 17:24 ` Darren Hart
2012-06-15 18:45 Ingo Molnar
2012-01-26 18:05 Ingo Molnar
2011-08-04 20:45 Ingo Molnar
2011-04-02 10:21 Ingo Molnar
2011-03-25 12:52 Ingo Molnar
2011-01-21 2:11 Ingo Molnar
2011-01-15 15:15 Ingo Molnar
2010-10-05 19:12 Ingo Molnar
2010-10-05 20:15 ` Linus Torvalds
2010-10-05 21:09 ` Paul E. McKenney
2010-10-05 21:45 ` Linus Torvalds
2010-10-05 22:05 ` Paul E. McKenney
2010-10-06 2:56 ` Eric Dumazet
2010-10-06 4:59 ` Paul E. McKenney
2010-10-06 18:20 ` Ingo Molnar
2010-10-06 21:27 ` Paul E. McKenney
2010-10-07 8:11 ` Ingo Molnar
2010-10-07 17:42 ` Paul E. McKenney
2010-09-08 13:04 Ingo Molnar
2010-03-26 14:53 Ingo Molnar
2010-03-13 16:35 Ingo Molnar
2009-12-18 18:52 Ingo Molnar
2009-11-10 17:53 Ingo Molnar
2009-10-23 14:53 Ingo Molnar
2009-10-13 18:29 Ingo Molnar
2009-10-08 19:06 Ingo Molnar
2009-10-08 19:16 ` Linus Torvalds
2009-10-08 19:20 ` Ingo Molnar
2009-09-21 13:13 Ingo Molnar
2009-08-13 18:54 Ingo Molnar
2009-08-09 16:07 Ingo Molnar
2009-08-09 18:41 ` Darren Hart
2009-07-10 16:28 Ingo Molnar
2009-07-10 19:06 ` Linus Torvalds
2009-07-10 19:31 ` Ingo Molnar
2009-07-10 19:52 ` Linus Torvalds
2009-07-10 20:02 ` Ingo Molnar
2009-07-13 14:52 ` Joerg Roedel
2009-06-20 17:30 Ingo Molnar
2009-06-20 18:49 ` Linus Torvalds
2009-06-20 19:01 ` Linus Torvalds
2009-06-20 20:27 ` Ingo Molnar
2009-06-21 17:12 ` Thomas Gleixner
2009-06-21 17:37 ` Linus Torvalds
2009-06-21 17:57 ` Linus Torvalds
2009-06-21 19:26 ` Thomas Gleixner
2009-05-18 14:23 Ingo Molnar
2009-05-18 15:48 ` Linus Torvalds
2009-05-18 19:20 ` Thomas Gleixner
2009-05-19 20:52 ` Linus Torvalds
2009-05-19 21:45 ` Thomas Gleixner
2009-05-19 22:20 ` Darren Hart
2009-05-05 9:33 Ingo Molnar
2009-01-26 17:24 [git pull] " Ingo Molnar
2009-01-11 14:36 Ingo Molnar
2008-12-04 19:39 Ingo Molnar
2008-11-29 19:36 Ingo Molnar
2008-11-18 14:14 Ingo Molnar
2008-11-07 16:28 Ingo Molnar
2008-10-30 23:29 Ingo Molnar
2008-10-15 12:50 [git pull] core kernel updates for v2.6.28 Ingo Molnar
2008-10-16 22:32 ` Linus Torvalds
2008-10-17 6:23 ` [git pull] core kernel fixes Ingo Molnar
2008-08-28 11:44 Ingo Molnar
2008-08-18 18:35 Ingo Molnar
2008-07-24 15:13 Ingo Molnar
2008-06-30 15:32 Ingo Molnar
2008-06-30 17:02 ` Vegard Nossum
2008-06-30 18:20 ` Ingo Molnar
2008-06-30 18:43 ` Vegard Nossum
2008-06-30 19:46 ` Thomas Gleixner
2008-06-30 19:51 ` Vegard Nossum
2008-06-30 19:54 ` Thomas Gleixner
2008-06-23 19:45 Ingo Molnar
2008-06-19 15:16 Ingo Molnar
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