Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
time/timekeeping: Avoid invoking clock_was_set() twice
do_adjtimex() might end up scheduling a delayed clock_was_set() via
timekeeping_advance() and then invoke clock_was_set() directly which is
pointless.
Make timekeeping_advance() return whether an invocation of clock_was_set()
is required and handle it at the call sites which allows do_adjtimex() to
issue a single direct call if required.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210713135158.580966888@linutronix.de
+10
-8
+10
-8
kernel/time/timekeeping.c
+10
-8
kernel/time/timekeeping.c
···
2127
2127
* timekeeping_advance - Updates the timekeeper to the current time and
2128
2128
* current NTP tick length
2129
2129
*/
2130
-
static void timekeeping_advance(enum timekeeping_adv_mode mode)
2130
+
static bool timekeeping_advance(enum timekeeping_adv_mode mode)
2131
2131
{
2132
2132
struct timekeeper *real_tk = &tk_core.timekeeper;
2133
2133
struct timekeeper *tk = &shadow_timekeeper;
···
2198
2198
write_seqcount_end(&tk_core.seq);
2199
2199
out:
2200
2200
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
2201
-
if (clock_set)
2202
-
/* Have to call _delayed version, since in irq context*/
2203
-
clock_was_set_delayed();
2201
+
2202
+
return !!clock_set;
2204
2203
}
2205
2204
2206
2205
/**
···
2208
2209
*/
2209
2210
void update_wall_time(void)
2210
2211
{
2211
-
timekeeping_advance(TK_ADV_TICK);
2212
+
if (timekeeping_advance(TK_ADV_TICK))
2213
+
clock_was_set_delayed();
2212
2214
}
2213
2215
2214
2216
/**
···
2389
2389
{
2390
2390
struct timekeeper *tk = &tk_core.timekeeper;
2391
2391
struct audit_ntp_data ad;
2392
-
unsigned long flags;
2392
+
bool clock_set = false;
2393
2393
struct timespec64 ts;
2394
+
unsigned long flags;
2394
2395
s32 orig_tai, tai;
2395
2396
int ret;
2396
2397
···
2426
2425
if (tai != orig_tai) {
2427
2426
__timekeeping_set_tai_offset(tk, tai);
2428
2427
timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
2428
+
clock_set = true;
2429
2429
}
2430
2430
tk_update_leap_state(tk);
2431
2431
···
2437
2435
2438
2436
/* Update the multiplier immediately if frequency was set directly */
2439
2437
if (txc->modes & (ADJ_FREQUENCY | ADJ_TICK))
2440
-
timekeeping_advance(TK_ADV_FREQ);
2438
+
clock_set |= timekeeping_advance(TK_ADV_FREQ);
2441
2439
2442
-
if (tai != orig_tai)
2440
+
if (clock_set)
2443
2441
clock_was_set();
2444
2442
2445
2443
ntp_notify_cmos_timer();