Re: [Crash-utility] [PATCH] Fix machdep->HZ calculation for kernel versions > 2.6.0
-----Original Message-----
> As for the 'write_expire' way, I found that it can be
printed after
> "set scope dd_init_queue" or "set scope deadline_init_queue" on
old kernels.
>
> crash> p write_expire
> No symbol "write_expire" in current context.
> p: gdb request failed: p write_expire
> crash> set scope dd_init_queue
> scope: ffffffffa43e3f80 (dd_init_queue)
> crash> p write_expire
> $1 = 5000
>
> Maybe we can make use of gdb_set_crash_scope() and gdb_pass_through() to
> get this value?
>
The 'write_expire' is a static variable, which needs to get its value from
gdb. Seems that it is a bit complicated.
But It's worth having a try.
The following is a draft patch. It worked for some dumpfiles I have
from 2.6.16 to 5.11 including RHEL8.0 one. What do you think?
diff --git a/task.c b/task.c
index 423cd454502b..654df6b1220c 100644
--- a/task.c
+++ b/task.c
@@ -417,7 +417,33 @@ task_init(void)
STRUCT_SIZE_INIT(cputime_t, "cputime_t");
- if (symbol_exists("cfq_slice_async")) {
+ if ((symbol_exists("dd_init_queue") &&
+ gdb_set_crash_scope(symbol_value("dd_init_queue"),
"dd_init_queue")) ||
+ (symbol_exists("deadline_init_queue") &&
+ gdb_set_crash_scope(symbol_value("deadline_init_queue"),
"deadline_init_queue"))) {
+ char buf[BUFSIZE];
+ uint write_expire = 0;
+
+ open_tmpfile();
+ sprintf(buf, "printf \"%%d\", write_expire");
+ if (gdb_pass_through(buf, pc->tmpfile, GNU_RETURN_ON_ERROR)) {
+ rewind(pc->tmpfile);
+ while (fgets(buf, BUFSIZE, pc->tmpfile)) {
+ sscanf(buf, "%d", &write_expire);
+ }
+ }
+ close_tmpfile();
+
+ if (write_expire) {
+ machdep->hz = write_expire / 5;
+ if (CRASHDEBUG(2))
+ fprintf(fp, "write_expire exists: setting hz to %d\n",
+ machdep->hz);
+ }
+ fprintf(fp, "write_expire = %d, machdep->hz = %d\n", write_expire,
machdep->hz);
+ gdb_set_crash_scope(0, NULL);
+
+ } else if (symbol_exists("cfq_slice_async")) {
uint cfq_slice_async;
get_symbol_data("cfq_slice_async", sizeof(int),