Re: [Crash-utility] [PATCH] Add alternate HZ calculation using write_expire

在 2021年04月26日 09:37, HAGIO KAZUHITO(萩尾　一仁) 写道: > Linux 4.8 and later kernels that contain kernel commit 9a7f38c42c2b > ("cfq-iosched: Convert from jiffies to nanoseconds") changed the > definition of cfq_slice_async, and it cannot be used to calculate > the HZ value. > > Add alternate HZ calculation using write_expire, which depends on > CONFIG_MQ_IOSCHED_DEADLINE or CONFIG_IOSCHED_DEADLINE. > > Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com&gt; > --- > task.c | 23 +++++++++++++++++++++++ > 1 file changed, 23 insertions(+) > > diff --git a/task.c b/task.c > index ce2b55f430e0..36cf259e5d7b 100644 > --- a/task.c > +++ b/task.c > @@ -432,6 +432,29 @@ task_init(void) > "cfq_slice_async exists: setting hz to %d\n", > machdep->hz); > } > + } else 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); > + if (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); > + } > + gdb_set_crash_scope(0, NULL); > } > > if (VALID_MEMBER(runqueue_arrays)) > Acked-by: Lianbo Jiang <lijiang(a)redhat.com&gt;