Messages in this thread | | | Subject | Re: [PATCH v2] Add hard/soft lockup debugger entry points | From | Chris Metcalf <> | Date | Tue, 26 Jan 2016 12:22:35 -0500 |
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On 01/26/2016 12:04 PM, Jeff Merkey wrote: > This patch adds an export which can be set by system debuggers to direct > the hard lockup and soft lockup detector to trigger a breakpoint exception > and enter a debugger if one is active. It is assumed that if someone > sets this variable, then an breakpoint handler of some sort will be actively > loaded or registered via the notify die handler chain. > > This addition is extremely useful for debugging hard and soft lockups > real time and quickly from a console debugger. > > Signed-off-by: Jeff Merkey<linux.mdb@gmail.com> > --- > kernel/watchdog.c | 10 ++++++++++ > 1 file changed, 10 insertions(+)
You probably should reach out to someone who uses this stuff more regularly - I actually wonder if the kgdb_breakpoint() API is the right thing, though, not the internal arch_kgdb_breakpoint().
Of course any of these strategies also assume you are building the kernel with CONFIG_KGDB set, and I'm pretty sure will cause your build to fail if it isn't. You likely need to guard this stuff locally within watchdog.c for !CONFIG_KGDB.
-- Chris Metcalf, EZChip Semiconductor http://www.ezchip.com
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