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author | Douglas Anderson <dianders@chromium.org> | 2016-12-15 00:05:49 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-15 01:04:08 +0100 |
commit | 2d13bb6494c807bcf3f78af0e96c0b8615a94385 (patch) | |
tree | f81c9862fc1119f34eb9584aedeed49471613ea4 /samples/kdb | |
parent | kcov: add more missing includes (diff) | |
download | linux-2d13bb6494c807bcf3f78af0e96c0b8615a94385.tar.xz linux-2d13bb6494c807bcf3f78af0e96c0b8615a94385.zip |
kernel/debug/debug_core.c: more properly delay for secondary CPUs
We've got a delay loop waiting for secondary CPUs. That loop uses
loops_per_jiffy. However, loops_per_jiffy doesn't actually mean how
many tight loops make up a jiffy on all architectures. It is quite
common to see things like this in the boot log:
Calibrating delay loop (skipped), value calculated using timer
frequency.. 48.00 BogoMIPS (lpj=24000)
In my case I was seeing lots of cases where other CPUs timed out
entering the debugger only to print their stack crawls shortly after the
kdb> prompt was written.
Elsewhere in kgdb we already use udelay(), so that should be safe enough
to use to implement our timeout. We'll delay 1 ms for 1000 times, which
should give us a full second of delay (just like the old code wanted)
but allow us to notice that we're done every 1 ms.
[akpm@linux-foundation.org: simplifications, per Daniel]
Link: http://lkml.kernel.org/r/1477091361-2039-1-git-send-email-dianders@chromium.org
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Brian Norris <briannorris@chromium.org>
Cc: <stable@vger.kernel.org> [4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'samples/kdb')
0 files changed, 0 insertions, 0 deletions