s390/vtime: correct scaled cputime of partially idle CPUs

The calculation for the SMT scaling factor for a hardware thread
which has been partially idle needs to disregard the cycles spent
by the other threads of the core while the thread is idle.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2015-09-18 16:41:36 +02:00
parent adc0b7fbf6
commit 72d38b1978
3 changed files with 67 additions and 30 deletions

View File

@@ -733,6 +733,14 @@ ENTRY(psw_idle)
stg %r3,__SF_EMPTY(%r15)
larl %r1,.Lpsw_idle_lpsw+4
stg %r1,__SF_EMPTY+8(%r15)
#ifdef CONFIG_SMP
larl %r1,smp_cpu_mtid
llgf %r1,0(%r1)
ltgr %r1,%r1
jz .Lpsw_idle_stcctm
.insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+16(%r15)
.Lpsw_idle_stcctm:
#endif
STCK __CLOCK_IDLE_ENTER(%r2)
stpt __TIMER_IDLE_ENTER(%r2)
.Lpsw_idle_lpsw:
@@ -1159,7 +1167,27 @@ cleanup_critical:
jhe 1f
mvc __CLOCK_IDLE_ENTER(8,%r2),__CLOCK_IDLE_EXIT(%r2)
mvc __TIMER_IDLE_ENTER(8,%r2),__TIMER_IDLE_EXIT(%r2)
1: # account system time going idle
1: # calculate idle cycles
#ifdef CONFIG_SMP
clg %r9,BASED(.Lcleanup_idle_insn)
jl 3f
larl %r1,smp_cpu_mtid
llgf %r1,0(%r1)
ltgr %r1,%r1
jz 3f
.insn rsy,0xeb0000000017,%r1,5,__SF_EMPTY+80(%r15)
larl %r3,mt_cycles
ag %r3,__LC_PERCPU_OFFSET
la %r4,__SF_EMPTY+16(%r15)
2: lg %r0,0(%r3)
slg %r0,0(%r4)
alg %r0,64(%r4)
stg %r0,0(%r3)
la %r3,8(%r3)
la %r4,8(%r4)
brct %r1,2b
#endif
3: # account system time going idle
lg %r9,__LC_STEAL_TIMER
alg %r9,__CLOCK_IDLE_ENTER(%r2)
slg %r9,__LC_LAST_UPDATE_CLOCK