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| author | Arnd Bergmann <arnd@arndb.de> | 2019-07-10 15:01:53 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-10 20:37:49 +0200 |
| commit | 0df1c9868c3a1916198ee09c323ca5932a0b8a11 (patch) | |
| tree | 18a8b26434edf1c7766d971bbcdbc3c516c2205d | |
| parent | 9bdd7bb3a8447fe841cd37ddd9e0a6974b06a0bb (diff) | |
| download | linux-0df1c9868c3a1916198ee09c323ca5932a0b8a11.tar.bz2 | |
timekeeping/vsyscall: Use __iter_div_u64_rem()
On 32-bit x86 when building with clang-9, the 'division' loop gets turned
back into an inefficient division that causes a link error:
kernel/time/vsyscall.o: In function `update_vsyscall':
vsyscall.c:(.text+0xe3): undefined reference to `__udivdi3'
Use the existing __iter_div_u64_rem() function which is used to address the
same issue in other places.
Fixes: 44f57d788e7d ("timekeeping: Provide a generic update_vsyscall() implementation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lkml.kernel.org/r/20190710130206.1670830-1-arnd@arndb.de
| -rw-r--r-- | kernel/time/vsyscall.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c index a80893180826..8cf3596a4ce6 100644 --- a/kernel/time/vsyscall.c +++ b/kernel/time/vsyscall.c @@ -104,11 +104,7 @@ void update_vsyscall(struct timekeeper *tk) vdso_ts->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec; nsec = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift; nsec = nsec + tk->wall_to_monotonic.tv_nsec; - while (nsec >= NSEC_PER_SEC) { - nsec = nsec - NSEC_PER_SEC; - vdso_ts->sec++; - } - vdso_ts->nsec = nsec; + vdso_ts->sec += __iter_div_u64_rem(nsec, NSEC_PER_SEC, &vdso_ts->nsec); if (__arch_use_vsyscall(vdata)) update_vdso_data(vdata, tk); |