On Sat, Nov 17, 2018 at 12:02 AM <valdis.kletnieks@xxxxxx> wrote: > > On Fri, 16 Nov 2018 23:13:48 +0530, Pintu Agarwal said: > > On Fri, Nov 16, 2018 at 10:16 PM <valdis.kletnieks@xxxxxx> wrote: > > > > Congrats. You just re-invented DEBUG_STACK_USAGE, which just keeps a high-water mark > > > for stack usage. > > > > So, you mean to say, my implementation is good enough to get the > > irq_stack usage, from the interrupt handler ? > > No - your code doesn't keep a high-water mark (which should probably be > hooked into the IRQ exit code. > > > But my concern is that if I dump it from irq handler, I will get > > information only for the current cpu. > > How do I store and get the information for all the cpu from the boot time ? > > Make the high-water mark a per-cpu variable. > > > From where do I call my dump_irq_stack_info() [some where during the > > entry/exit part of the irq handler], so that I could dump information > > for all the handler at boot time itself ? > > No, you don't do a dump-stack during entry/exit. You just maintain a high-water > value in the exit, Which is the right place to keep track of this high-water-irq-stack-usage (per_cpu) in arch/arm64/* ? > and then you create a /proc/something or similar that when > read does a 'foreach CPU do print_high_water_irq'. > Ok got it. > > Like I would to capture these information: > > - What was the name of the handler ? > > - Which cpu was executing it ? > > - How much irq stack (max value, same like high water mark) were used > > at that time ? > > First, do the easy part and find out if you even *care* once you see actual > numbers. If your IRQ stack is 8K but you never use more than 2500 bytes, > do you *really* care about the name of the handler anymore? > Hmm, yes, getting the name of the handler is not so important in the first run. > Also, see the code for /proc/interrupts to see how it keeps track of the > interrupts per CPU - maybe all you need to do is change each entry from > a 'count' to 'count, highwater'. Ok thanks, thats a good pointer. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
