Displaying 5 results from an estimated 5 matches for "gtod_read_begin".
2018 Sep 17
11
[patch V2 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support
Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime()
implementation, which extended the clockid switch case and added yet
another slightly different copy of the same code.
Especially the extended switch case is problematic as the compiler tends to
generate a jump table which then requires to use retpolines. If jump tables
are disabled it adds yet another conditional to the existing
2018 Sep 14
24
[patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support
Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime()
implementation, which extended the clockid switch case and added yet
another slightly different copy of the same code.
Especially the extended switch case is problematic as the compiler tends to
generate a jump table which then requires to use retpolines. If jump tables
are disabled it adds yet another conditional to the existing
2018 Sep 14
24
[patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support
Matt attempted to add CLOCK_TAI support to the VDSO clock_gettime()
implementation, which extended the clockid switch case and added yet
another slightly different copy of the same code.
Especially the extended switch case is problematic as the compiler tends to
generate a jump table which then requires to use retpolines. If jump tables
are disabled it adds yet another conditional to the existing
2018 Sep 14
0
[patch 10/11] x86/vdso: Move cycle_last handling into the caller
...VCLOCK)
return vread_pvclock();
@@ -168,17 +141,19 @@ notrace static inline u64 vgetcyc(int mo
notrace static int do_hres(clockid_t clk, struct timespec *ts)
{
struct vgtod_ts *base = >od->basetime[clk];
+ u64 cycles, last, ns;
unsigned int seq;
- u64 cycles, ns;
do {
seq = gtod_read_begin(gtod);
ts->tv_sec = base->sec;
ns = base->nsec;
+ last = gtod->cycle_last;
cycles = vgetcyc(gtod->vclock_mode);
if (unlikely((s64)cycles < 0))
return vdso_fallback_gettime(clk, ts);
- ns += (cycles - gtod->cycle_last) * gtod->mult;
+ if (cycles > last)...
2018 Sep 14
0
[patch 09/11] x86/vdso: Simplify the invalid vclock case
...- return 0;
- v = cycles - gtod->cycle_last;
- return v * gtod->mult;
+ return U64_MAX;
}
notrace static int do_hres(clockid_t clk, struct timespec *ts)
{
struct vgtod_ts *base = >od->basetime[clk];
unsigned int seq;
- int mode;
- u64 ns;
+ u64 cycles, ns;
do {
seq = gtod_read_begin(gtod);
- mode = gtod->vclock_mode;
ts->tv_sec = base->sec;
ns = base->nsec;
- ns += vgetsns(&mode);
+ cycles = vgetcyc(gtod->vclock_mode);
+ if (unlikely((s64)cycles < 0))
+ return vdso_fallback_gettime(clk, ts);
+ ns += (cycles - gtod->cycle_last) * gtod->m...