Commit 4441b976 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Thomas Gleixner
Browse files

hrtimers: Replace hrtimer_clock_to_base_table with switch-case 



Clang and GCC complain about overlapped initialisers in the
hrtimer_clock_to_base_table definition. With `make W=1` and CONFIG_WERROR=y
(which is default nowadays) this breaks the build:

  CC      kernel/time/hrtimer.o
kernel/time/hrtimer.c:124:21: error: initializer overrides prior initialization of this subobject [-Werror,-Winitializer-overrides]
  124 |         [CLOCK_REALTIME]        = HRTIMER_BASE_REALTIME,

kernel/time/hrtimer.c:122:27: note: previous initialization is here
  122 |         [0 ... MAX_CLOCKS - 1]  = HRTIMER_MAX_CLOCK_BASES,

(and similar for CLOCK_MONOTONIC, CLOCK_BOOTTIME, and CLOCK_TAI).

hrtimer_clockid_to_base(), which uses the table, is only used in
__hrtimer_init(), which is not a hotpath.

Therefore replace the table lookup with a switch case in
hrtimer_clockid_to_base() to avoid this warning.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20250214134424.3367619-1-andriy.shevchenko@linux.intel.com
parent 2ea97b76

kernel/time/hrtimer.c

+12 −17
Original line number Diff line number Diff line
@@ -117,16 +117,6 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = 
	.csd = CSD_INIT(retrigger_next_event, NULL)

};



static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {

	/* Make sure we catch unsupported clockids */

	[0 ... MAX_CLOCKS - 1]	= HRTIMER_MAX_CLOCK_BASES,



	[CLOCK_REALTIME]	= HRTIMER_BASE_REALTIME,

	[CLOCK_MONOTONIC]	= HRTIMER_BASE_MONOTONIC,

	[CLOCK_BOOTTIME]	= HRTIMER_BASE_BOOTTIME,

	[CLOCK_TAI]		= HRTIMER_BASE_TAI,

};



static inline bool hrtimer_base_is_online(struct hrtimer_cpu_base *base)

{

	if (!IS_ENABLED(CONFIG_HOTPLUG_CPU))
@@ -1587,15 +1577,20 @@ u64 hrtimer_next_event_without(const struct hrtimer *exclude) 


static inline int hrtimer_clockid_to_base(clockid_t clock_id)

{

	if (likely(clock_id < MAX_CLOCKS)) {

		int base = hrtimer_clock_to_base_table[clock_id];



		if (likely(base != HRTIMER_MAX_CLOCK_BASES))

			return base;

	}

	switch (clock_id) {

	case CLOCK_REALTIME:

		return HRTIMER_BASE_REALTIME;

	case CLOCK_MONOTONIC:

		return HRTIMER_BASE_MONOTONIC;

	case CLOCK_BOOTTIME:

		return HRTIMER_BASE_BOOTTIME;

	case CLOCK_TAI:

		return HRTIMER_BASE_TAI;

	default:

		WARN(1, "Invalid clockid %d. Using MONOTONIC\n", clock_id);

		return HRTIMER_BASE_MONOTONIC;

	}

}



static enum hrtimer_restart hrtimer_dummy_timeout(struct hrtimer *unused)

{