| Message ID | 20230130130246.247537-1-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | f94fe7048a352ff8914232a18e2e2f18f8a5ac81 |
| Headers | show |
| Series | ftrace: sample: avoid open-coded 64-bit division | expand |
On Mon, Jan 30, 2023 at 02:02:37PM +0100, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@arndb.de> > > Calculating the average period requires a 64-bit division that leads > to a link failure on 32-bit architectures: > > x86_64-linux-ld: samples/ftrace/ftrace-ops.o: in function `ftrace_ops_sample_init': > ftrace-ops.c:(.init.text+0x23b): undefined reference to `__udivdi3' Whoops; sorry about that. > Use the div_u64() helper to do this instead. Since this is an init function that > is not called frequently, the runtime overhead is going to be acceptable. > > Fixes: b56c68f705ca ("ftrace: Add sample with custom ops") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Mark. > --- > samples/ftrace/ftrace-ops.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/samples/ftrace/ftrace-ops.c b/samples/ftrace/ftrace-ops.c > index 24deb51c7261..0c8da87ff5c3 100644 > --- a/samples/ftrace/ftrace-ops.c > +++ b/samples/ftrace/ftrace-ops.c > @@ -223,7 +223,7 @@ static int __init ftrace_ops_sample_init(void) > > pr_info("Attempted %u calls to %ps in %lluns (%lluns / call)\n", > nr_function_calls, tracee_relevant, > - period, period / nr_function_calls); > + period, div_u64(period, nr_function_calls)); > > if (persist) > return 0; > -- > 2.39.0 >
diff --git a/samples/ftrace/ftrace-ops.c b/samples/ftrace/ftrace-ops.c index 24deb51c7261..0c8da87ff5c3 100644 --- a/samples/ftrace/ftrace-ops.c +++ b/samples/ftrace/ftrace-ops.c @@ -223,7 +223,7 @@ static int __init ftrace_ops_sample_init(void) pr_info("Attempted %u calls to %ps in %lluns (%lluns / call)\n", nr_function_calls, tracee_relevant, - period, period / nr_function_calls); + period, div_u64(period, nr_function_calls)); if (persist) return 0;