add queue-2.6.23/softlockup-watchdog-fixes-and-cleanups.patch

diff --git a/queue-2.6.23/series b/queue-2.6.23/series
index 28363c7bffd98a0da19ee548729cb5d00ff0dfa4..ab0cbd8091da3b58ea40898a85d3016acbe0d997 100644 (file)
--- a/queue-2.6.23/series
+++ b/queue-2.6.23/series
@@ -22,3 +22,4 @@ x86-nx-bit-handling-in-change-page-attr.patch
 x98-return-correct-error-code-from-child-rip.patch
 ntp-fix-sync-cmos-clock-typo.patch
 x86-fix-rtc-locking.patch
+softlockup-watchdog-fixes-and-cleanups.patch

diff --git a/queue-2.6.23/softlockup-watchdog-fixes-and-cleanups.patch b/queue-2.6.23/softlockup-watchdog-fixes-and-cleanups.patch
new file mode 100644 (file)
index 0000000..0704dcf
--- /dev/null
+++ b/queue-2.6.23/softlockup-watchdog-fixes-and-cleanups.patch
@@ -0,0 +1,195 @@
+From mingo@elte.hu Sat Nov 17 16:56:05 2007
+From: Ingo Molnar <mingo@elte.hu>
+Date: Sun, 18 Nov 2007 01:55:38 +0100
+Subject: softlockup watchdog fixes and cleanups
+To: Greg KH <greg@kroah.com>
+Cc: David <david@unsolicited.net>, Jeremy Fitzhardinge <jeremy@goop.org>, gregkh@suse.de, Javier Kohen <jkohen@users.sourceforge.net>, Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org, stable@kernel.org
+Message-ID: <20071118005538.GD26865@elte.hu>
+Content-Disposition: inline
+
+From: Ingo Molnar <mingo@elte.hu>
+
+
+This is a merge of commits a5f2ce3c6024a5bb895647b6bd88ecae5001020a and
+43581a10075492445f65234384210492ff333eba in mainline to fix a warning in
+the 2.6.23.3 kernel release.
+
+softlockup watchdog: style cleanups
+
+kernel/softirq.c grew a few style uncleanlinesses in the past few
+months, clean that up. No functional changes:
+
+text    data     bss     dec     hex filename
+1126      76       4    1206     4b6 softlockup.o.before
+1129      76       4    1209     4b9 softlockup.o.after
+
+( the 3 bytes .text increase is due to the "<1>" appended to one of
+the printk messages. )
+
+Signed-off-by: Ingo Molnar <mingo@elte.hu>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+
+
+softlockup: improve debug output
+
+Improve the debuggability of kernel lockups by enhancing the debug
+output of the softlockup detector: print the task that causes the lockup
+and try to print a more intelligent backtrace.
+
+The old format was:
+
+BUG: soft lockup detected on CPU#1!
+[<c0105e4a>] show_trace_log_lvl+0x19/0x2e
+[<c0105f43>] show_trace+0x12/0x14
+[<c0105f59>] dump_stack+0x14/0x16
+[<c015f6bc>] softlockup_tick+0xbe/0xd0
+[<c013457d>] run_local_timers+0x12/0x14
+[<c01346b8>] update_process_times+0x3e/0x63
+[<c0145fb8>] tick_sched_timer+0x7c/0xc0
+[<c0140a75>] hrtimer_interrupt+0x135/0x1ba
+[<c011bde7>] smp_apic_timer_interrupt+0x6e/0x80
+[<c0105aa3>] apic_timer_interrupt+0x33/0x38
+[<c0104f8a>] syscall_call+0x7/0xb
+=======================
+
+The new format is:
+
+BUG: soft lockup detected on CPU#1! [prctl:2363]
+
+Pid: 2363, comm:                prctl
+EIP: 0060:[<c013915f>] CPU: 1
+EIP is at sys_prctl+0x24/0x18c
+EFLAGS: 00000213    Not tainted  (2.6.22-cfs-v20 #26)
+EAX: 00000001 EBX: 000003e7 ECX: 00000001 EDX: f6df0000
+ESI: 000003e7 EDI: 000003e7 EBP: f6df0fb0 DS: 007b ES: 007b FS: 00d8
+CR0: 8005003b CR2: 4d8c3340 CR3: 3731d000 CR4: 000006d0
+[<c0105e4a>] show_trace_log_lvl+0x19/0x2e
+[<c0105f43>] show_trace+0x12/0x14
+[<c01040be>] show_regs+0x1ab/0x1b3
+[<c015f807>] softlockup_tick+0xef/0x108
+[<c013457d>] run_local_timers+0x12/0x14
+[<c01346b8>] update_process_times+0x3e/0x63
+[<c0145fcc>] tick_sched_timer+0x7c/0xc0
+[<c0140a89>] hrtimer_interrupt+0x135/0x1ba
+[<c011bde7>] smp_apic_timer_interrupt+0x6e/0x80
+[<c0105aa3>] apic_timer_interrupt+0x33/0x38
+[<c0104f8a>] syscall_call+0x7/0xb
+=======================
+
+Note that in the old format we only knew that some system call locked
+up, we didnt know _which_. With the new format we know that it's at a
+specific place in sys_prctl(). [which was where i created an artificial
+kernel lockup to test the new format.]
+
+This is also useful if the lockup happens in user-space - the user-space
+EIP (and other registers) will be printed too. (such a lockup would
+either suggest that the task was running at SCHED_FIFO:99 and looping
+for more than 10 seconds, or that the softlockup detector has a
+false-positive.)
+
+The task name is printed too first, just in case we dont manage to print
+a useful backtrace.
+
+[satyam@infradead.org: fix warning]
+Signed-off-by: Ingo Molnar <mingo@elte.hu>
+Signed-off-by: Satyam Sharma <satyam@infradead.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+
+---
+ kernel/softlockup.c |   37 +++++++++++++++++++++++--------------
+ 1 file changed, 23 insertions(+), 14 deletions(-)
+
+--- a/kernel/softlockup.c
++++ b/kernel/softlockup.c
+@@ -15,13 +15,16 @@
+ #include <linux/notifier.h>
+ #include <linux/module.h>
+ 
++#include <asm/irq_regs.h>
++
+ static DEFINE_SPINLOCK(print_lock);
+ 
+ static DEFINE_PER_CPU(unsigned long, touch_timestamp);
+ static DEFINE_PER_CPU(unsigned long, print_timestamp);
+ static DEFINE_PER_CPU(struct task_struct *, watchdog_task);
+ 
+-static int did_panic = 0;
++static int did_panic;
++int softlockup_thresh = 10;
+ 
+ static int
+ softlock_panic(struct notifier_block *this, unsigned long event, void *ptr)
+@@ -70,6 +73,7 @@ void softlockup_tick(void)
+       int this_cpu = smp_processor_id();
+       unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu);
+       unsigned long print_timestamp;
++      struct pt_regs *regs = get_irq_regs();
+       unsigned long now;
+ 
+       if (touch_timestamp == 0) {
+@@ -99,21 +103,26 @@ void softlockup_tick(void)
+               wake_up_process(per_cpu(watchdog_task, this_cpu));
+ 
+       /* Warn about unreasonable 10+ seconds delays: */
+-      if (now > (touch_timestamp + 10)) {
+-              per_cpu(print_timestamp, this_cpu) = touch_timestamp;
++      if (now <= (touch_timestamp + softlockup_thresh))
++              return;
++
++      per_cpu(print_timestamp, this_cpu) = touch_timestamp;
+ 
+-              spin_lock(&print_lock);
+-              printk(KERN_ERR "BUG: soft lockup detected on CPU#%d!\n",
+-                      this_cpu);
++      spin_lock(&print_lock);
++      printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n",
++                      this_cpu, now - touch_timestamp,
++                      current->comm, current->pid);
++      if (regs)
++              show_regs(regs);
++      else
+               dump_stack();
+-              spin_unlock(&print_lock);
+-      }
++      spin_unlock(&print_lock);
+ }
+ 
+ /*
+  * The watchdog thread - runs every second and touches the timestamp.
+  */
+-static int watchdog(void * __bind_cpu)
++static int watchdog(void *__bind_cpu)
+ {
+       struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
+ 
+@@ -151,13 +160,13 @@ cpu_callback(struct notifier_block *nfb,
+               BUG_ON(per_cpu(watchdog_task, hotcpu));
+               p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu);
+               if (IS_ERR(p)) {
+-                      printk("watchdog for %i failed\n", hotcpu);
++                      printk(KERN_ERR "watchdog for %i failed\n", hotcpu);
+                       return NOTIFY_BAD;
+               }
+-              per_cpu(touch_timestamp, hotcpu) = 0;
+-              per_cpu(watchdog_task, hotcpu) = p;
++              per_cpu(touch_timestamp, hotcpu) = 0;
++              per_cpu(watchdog_task, hotcpu) = p;
+               kthread_bind(p, hotcpu);
+-              break;
++              break;
+       case CPU_ONLINE:
+       case CPU_ONLINE_FROZEN:
+               wake_up_process(per_cpu(watchdog_task, hotcpu));
+@@ -177,7 +186,7 @@ cpu_callback(struct notifier_block *nfb,
+               kthread_stop(p);
+               break;
+ #endif /* CONFIG_HOTPLUG_CPU */
+-      }
++      }
+       return NOTIFY_OK;
+ }
+