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kernel: fix tprof on multiprocessor

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segclock() has to be called from hzclock(), otherwise
only processes running on cpu0 would catche the interrupt
and the time delta would be wrong.

lock the segment when allocating Seg->profile as
profile ctl might be issued from multiple processes.
Proc->debug qlock is not sufficient.

Seg->profile can never be freed or reallocated once
set as the timer interrupt accesses it without any
locking.
This commit is contained in:
cinap_lenrek 2018-12-05 01:43:19 +01:00
parent 79bfff6437
commit d15aca0532
3 changed files with 26 additions and 28 deletions
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41
sys/src/9/port/devproc.c
View file

@ -1,6 +1,5 @@
#include "u.h"
#include <trace.h>
#include "tos.h"
#include "../port/lib.h"
#include "mem.h"
#include "dat.h"
@ -167,22 +166,6 @@ static int topens;
static int tproduced, tconsumed;
void (*proctrace)(Proc*, int, vlong);
static void
profclock(Ureg *ur, Timer *)
{
Tos *tos;
if(up == nil || up->state != Running)
return;
/* user profiling clock */
if(userureg(ur)){
tos = (Tos*)(USTKTOP-sizeof(Tos));
tos->clock += TK2MS(1);
segclock(ur->pc);
}
}
static int lenwatchpt(Proc *);
static int
@ -304,7 +287,6 @@ procinit(void)
{
if(conf.nproc >= (1<<(16-QSHIFT))-1)
print("warning: too many procs for devproc\n");
addclock0link((void (*)(void))profclock, 113); /* Relative prime to HZ */
}
static Chan*
@ -1454,7 +1436,8 @@ void
procctlreq(Proc *p, char *va, int n)
{
Segment *s;
int npc, pri;
uintptr npc;
int pri;
Cmdbuf *cb;
Cmdtab *ct;
vlong time;
@ -1520,14 +1503,20 @@ procctlreq(Proc *p, char *va, int n)
break;
case CMprofile:
s = p->seg[TSEG];
if(s == nil || (s->type&SG_TYPE) != SG_TEXT)
error(Ebadctl);
if(s->profile != nil)
free(s->profile);
if(s == nil || (s->type&SG_TYPE) != SG_TEXT) /* won't expand */
error(Egreg);
eqlock(s);
npc = (s->top-s->base)>>LRESPROF;
s->profile = malloc(npc*sizeof(*s->profile));
if(s->profile == nil)
error(Enomem);
if(s->profile == nil){
s->profile = malloc(npc*sizeof(*s->profile));
if(s->profile == nil){
qunlock(s);
error(Enomem);
}
} else {
memset(s->profile, 0, npc*sizeof(*s->profile));
}
qunlock(s);
break;
case CMstart:
if(p->state != Stopped)

11
sys/src/9/port/portclock.c
View file

@ -5,6 +5,7 @@
#include "fns.h"
#include "io.h"
#include "ureg.h"
#include "tos.h"
struct Timers
{
@ -167,8 +168,16 @@ hzclock(Ureg *ur)
if(m->machno == 0)
checkalarms();
if(up && up->state == Running)
if(up && up->state == Running){
if(userureg(ur)){
/* user profiling clock */
Tos *tos = (Tos*)(USTKTOP-sizeof(Tos));
tos->clock += TK2MS(1);
segclock(ur->pc);
}
hzsched(); /* in proc.c */
}
}
void

2
sys/src/9/port/portmkfile
View file

@ -87,7 +87,7 @@ screen.$O: screen.h /sys/include/draw.h /sys/include/memdraw.h /sys/include/curs
thwack.$O: ../port/thwack.h
unthwack.$O: ../port/thwack.h
devsdp.$O: ../port/thwack.h
devproc.$O sysproc.$O: /sys/include/tos.h
portclock.$O sysproc.$O: /sys/include/tos.h
devproc.$O edf.$O proc.$O: /sys/include/trace.h
auth.$O devcons.$O: /sys/include/authsrv.h
devcap.$O: /sys/include/libsec.h