Dave Anderson wrote: > Hello Lai, > > If ever there was a perfect candidate for a crash utility extension module, > this is it. This functionality is far too subsystem-specific to included as > a generic command. There has not been a "new" base crash command in many years. > > Reviewing the patch, the "trace" command can easily be created as an extension > module. The only things that need to be done are: Your suggest is very helpful. We accept it. We're doing it now. Thank you very much. > > (2) Put the "int nr_cpu_ids" variable into the ftrace.c extension > module, where you still will have access to the global "kt" > kernel_table pointer. > There is a bug in my box: crash can not recognize the real cpus number, kt->cpus is wrong. So I fix it and put nr_cpu_ids in the kernel_table. I'll sent a separate patch for it soon. In current linux kernel, nr_cpu_ids is recommended to be used instead of old NR_CPUS. Because CONFIG_NR_CPUS=4096, it's too big for a lot of systems. kmalloc(sizeof(struct foo) * NR_CPUS) ==> kmalloc(sizeof(struct foo) * nr_cpu_ids) for (i=0; i < NR_CPUS; i++) ==> for (i=0; i < nr_cpu_ids; i++) NR_CPUS is also 4096 in crash now, so I also suggest using nr_cpu_ids instead of NR_CPUS in crash's code when the symbol "nr_cpu_ids" exists.