diff options
author | Paul E. McKenney <paul.mckenney@linaro.org> | 2012-09-21 13:41:50 -0400 |
---|---|---|
committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2012-09-23 10:42:52 -0400 |
commit | 86f343b50bb9f56cce60fade22da9defff28934c (patch) | |
tree | c2951c5b76afcd56a3d9f4a5d1d40e95528f3bbe /Documentation/RCU/stallwarn.txt | |
parent | 22a767269a767b3ee91e4aaea353ac6bec6a912d (diff) |
rcu: Fix CONFIG_RCU_FAST_NO_HZ stall warning message
The print_cpu_stall_fast_no_hz() function attempts to print -1 when
the ->idle_gp_timer is not pending, but unsigned arithmetic causes it
to instead print ULONG_MAX, which is 4294967295 on 32-bit systems and
18446744073709551615 on 64-bit systems. Neither of these are the most
reader-friendly values, so this commit instead causes "timer not pending"
to be printed when ->idle_gp_timer is not pending.
Reported-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU/stallwarn.txt')
-rw-r--r-- | Documentation/RCU/stallwarn.txt | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/Documentation/RCU/stallwarn.txt b/Documentation/RCU/stallwarn.txt index 523364e4e1f1..1927151b386b 100644 --- a/Documentation/RCU/stallwarn.txt +++ b/Documentation/RCU/stallwarn.txt | |||
@@ -99,7 +99,7 @@ In kernels with CONFIG_RCU_FAST_NO_HZ, even more information is | |||
99 | printed: | 99 | printed: |
100 | 100 | ||
101 | INFO: rcu_preempt detected stall on CPU | 101 | INFO: rcu_preempt detected stall on CPU |
102 | 0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 drain=0 . timer=-1 | 102 | 0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 drain=0 . timer not pending |
103 | (t=65000 jiffies) | 103 | (t=65000 jiffies) |
104 | 104 | ||
105 | The "(64628 ticks this GP)" indicates that this CPU has taken more | 105 | The "(64628 ticks this GP)" indicates that this CPU has taken more |
@@ -116,13 +116,13 @@ number between the two "/"s is the value of the nesting, which will | |||
116 | be a small positive number if in the idle loop and a very large positive | 116 | be a small positive number if in the idle loop and a very large positive |
117 | number (as shown above) otherwise. | 117 | number (as shown above) otherwise. |
118 | 118 | ||
119 | For CONFIG_RCU_FAST_NO_HZ kernels, the "drain=0" indicates that the | 119 | For CONFIG_RCU_FAST_NO_HZ kernels, the "drain=0" indicates that the CPU is |
120 | CPU is not in the process of trying to force itself into dyntick-idle | 120 | not in the process of trying to force itself into dyntick-idle state, the |
121 | state, the "." indicates that the CPU has not given up forcing RCU | 121 | "." indicates that the CPU has not given up forcing RCU into dyntick-idle |
122 | into dyntick-idle mode (it would be "H" otherwise), and the "timer=-1" | 122 | mode (it would be "H" otherwise), and the "timer not pending" indicates |
123 | indicates that the CPU has not recented forced RCU into dyntick-idle | 123 | that the CPU has not recently forced RCU into dyntick-idle mode (it |
124 | mode (it would otherwise indicate the number of microseconds remaining | 124 | would otherwise indicate the number of microseconds remaining in this |
125 | in this forced state). | 125 | forced state). |
126 | 126 | ||
127 | 127 | ||
128 | Multiple Warnings From One Stall | 128 | Multiple Warnings From One Stall |