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kernel: dont use atomic increment for Proc.nlocks, maintain Lock.m for lock(), use uintptr intstead of long for pc values

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change Proc.nlocks from Ref to int and just use normal increment and decrelemt
as done in erik quanstros 9atom.

It is not clear why we used atomic increment in the fist place as even if we
get preempted by interrupt and scheduled before we write back the incremented
value, it shouldnt be a problem and we'll just continue where we left off as
our process is the only one that can write to it.

Yoann Padioleau found that the Mach pointer Lock.m wasnt maintained
consistently for lock() vs canlock() and ilock(). Fixed.

Use uintptr instead of ulong for maxlockpc, maxilockpc and ilockpc debug variables.
This commit is contained in:
cinap_lenrek 2014-06-05 21:54:32 +02:00
parent 76db435e3c
commit 91614f582f
6 changed files with 29 additions and 44 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
sys/src/9/port/allocb.c
View file

@ -65,7 +65,7 @@ allocb(int size)
if(up == nil)
panic("allocb without up: %#p", getcallerpc(&size));
while((b = _allocb(size)) == nil){
if(up->nlocks.ref || m->ilockdepth || !islo()){
if(up->nlocks || m->ilockdepth || !islo()){
xsummary();
mallocsummary();
panic("allocb: no memory for %d bytes", size);

6
sys/src/9/port/fault.c
View file

@ -14,10 +14,10 @@ fault(uintptr addr, int read)
if(up == nil)
panic("fault: nil up");
if(up->nlocks.ref){
if(up->nlocks){
Lock *l = up->lastlock;
print("fault: nlocks %ld, proc %lud %s, addr %#p, lock %#p, lpc %#p\n",
up->nlocks.ref, up->pid, up->text, addr, l, l ? l->pc : 0);
print("fault: nlocks %d, proc %lud %s, addr %#p, lock %#p, lpc %#p\n",
up->nlocks, up->pid, up->text, addr, l, l ? l->pc : 0);
}
pnd = up->notepending;

2
sys/src/9/port/portdat.h
View file

@ -718,7 +718,7 @@ struct Proc
Mach *wired;
Mach *mp; /* machine this process last ran on */
Ref nlocks; /* number of locks held by proc */
int nlocks; /* number of locks held by proc */
ulong delaysched;
ulong priority; /* priority level */
ulong basepri; /* base priority level */

14
sys/src/9/port/proc.c
View file

@ -137,7 +137,7 @@ sched(void)
* in the middle of taslock when a process holds a lock
* but Lock.p has not yet been initialized.
*/
if(up->nlocks.ref)
if(up->nlocks)
if(up->state != Moribund)
if(up->delaysched < 20
|| palloc.Lock.p == up
@ -632,7 +632,7 @@ newproc(void)
p->syserrstr = p->errbuf1;
p->errbuf0[0] = '\0';
p->errbuf1[0] = '\0';
p->nlocks.ref = 0;
p->nlocks = 0;
p->delaysched = 0;
p->trace = 0;
kstrdup(&p->user, "*nouser");
@ -742,9 +742,9 @@ sleep(Rendez *r, int (*f)(void*), void *arg)
s = splhi();
if(up->nlocks.ref)
print("process %lud sleeps with %lud locks held, last lock %#p locked at pc %#p, sleep called from %#p\n",
up->pid, up->nlocks.ref, up->lastlock, up->lastlock->pc, getcallerpc(&r));
if(up->nlocks)
print("process %lud sleeps with %d locks held, last lock %#p locked at pc %#p, sleep called from %#p\n",
up->pid, up->nlocks, up->lastlock, up->lastlock->pc, getcallerpc(&r));
lock(r);
lock(&up->rlock);
if(r->p){
@ -1289,9 +1289,9 @@ dumpaproc(Proc *p)
s = p->psstate;
if(s == 0)
s = statename[p->state];
print("%3lud:%10s pc %#p dbgpc %#p %8s (%s) ut %ld st %ld bss %lux qpc %#p nl %lud nd %lud lpc %#p pri %lud\n",
print("%3lud:%10s pc %#p dbgpc %#p %8s (%s) ut %ld st %ld bss %lux qpc %#p nl %d nd %lud lpc %#p pri %lud\n",
p->pid, p->text, p->pc, dbgpc(p), s, statename[p->state],
p->time[0], p->time[1], bss, p->qpc, p->nlocks.ref, p->delaysched,
p->time[0], p->time[1], bss, p->qpc, p->nlocks, p->delaysched,
p->lastlock ? p->lastlock->pc : 0, p->priority);
}

8
sys/src/9/port/qlock.c
View file

@ -22,8 +22,8 @@ eqlock(QLock *q)
if(m->ilockdepth != 0)
print("eqlock: %#p: ilockdepth %d\n", getcallerpc(&q), m->ilockdepth);
if(up != nil && up->nlocks.ref)
print("eqlock: %#p: nlocks %lud\n", getcallerpc(&q), up->nlocks.ref);
if(up != nil && up->nlocks)
print("eqlock: %#p: nlocks %d\n", getcallerpc(&q), up->nlocks);
if(up != nil && up->eql)
print("eqlock: %#p: eql %p\n", getcallerpc(&q), up->eql);
if(q->use.key == 0x55555555)
@ -70,8 +70,8 @@ qlock(QLock *q)
if(m->ilockdepth != 0)
print("qlock: %#p: ilockdepth %d\n", getcallerpc(&q), m->ilockdepth);
if(up != nil && up->nlocks.ref)
print("qlock: %#p: nlocks %lud\n", getcallerpc(&q), up->nlocks.ref);
if(up != nil && up->nlocks)
print("qlock: %#p: nlocks %d\n", getcallerpc(&q), up->nlocks);
if(up != nil && up->eql)
print("qlock: %#p: eql %p\n", getcallerpc(&q), up->eql);
if(q->use.key == 0x55555555)

41
sys/src/9/port/taslock.c
View file

@ -10,8 +10,8 @@ long maxlockcycles;
long maxilockcycles;
long cumlockcycles;
long cumilockcycles;
ulong maxlockpc;
ulong maxilockpc;
uintptr maxlockpc;
uintptr maxilockpc;
struct
{
@ -20,23 +20,6 @@ struct
ulong inglare;
} lockstats;
static void
inccnt(Ref *r)
{
_xinc(&r->ref);
}
static int
deccnt(Ref *r)
{
int x;
x = _xdec(&r->ref);
if(x < 0)
panic("deccnt pc=%#p", getcallerpc(&r));
return x;
}
static void
dumplockmem(char *tag, Lock *l)
{
@ -73,12 +56,13 @@ lock(Lock *l)
lockstats.locks++;
if(up)
inccnt(&up->nlocks); /* prevent being scheded */
up->nlocks++; /* prevent being scheded */
if(tas(&l->key) == 0){
if(up)
up->lastlock = l;
l->pc = pc;
l->p = up;
l->m = MACHP(m->machno);
l->isilock = 0;
#ifdef LOCKCYCLES
l->lockcycles = -lcycles();
@ -86,7 +70,7 @@ lock(Lock *l)
return 0;
}
if(up)
deccnt(&up->nlocks);
up->nlocks--;
lockstats.glare++;
for(;;){
@ -108,12 +92,13 @@ lock(Lock *l)
}
}
if(up)
inccnt(&up->nlocks);
up->nlocks++;
if(tas(&l->key) == 0){
if(up)
up->lastlock = l;
l->pc = pc;
l->p = up;
l->m = MACHP(m->machno);
l->isilock = 0;
#ifdef LOCKCYCLES
l->lockcycles = -lcycles();
@ -121,7 +106,7 @@ lock(Lock *l)
return 1;
}
if(up)
deccnt(&up->nlocks);
up->nlocks--;
}
}
@ -159,8 +144,8 @@ acquire:
l->sr = x;
l->pc = pc;
l->p = up;
l->isilock = 1;
l->m = MACHP(m->machno);
l->isilock = 1;
#ifdef LOCKCYCLES
l->lockcycles = -lcycles();
#endif
@ -170,10 +155,10 @@ int
canlock(Lock *l)
{
if(up)
inccnt(&up->nlocks);
up->nlocks++;
if(tas(&l->key)){
if(up)
deccnt(&up->nlocks);
up->nlocks--;
return 0;
}
@ -210,7 +195,7 @@ unlock(Lock *l)
l->key = 0;
coherence();
if(up && deccnt(&up->nlocks) == 0 && up->delaysched && islo()){
if(up && --up->nlocks == 0 && up->delaysched && islo()){
/*
* Call sched if the need arose while locks were held
* But, don't do it from interrupt routines, hence the islo() test
@ -219,7 +204,7 @@ unlock(Lock *l)
}
}
ulong ilockpcs[0x100] = { [0xff] = 1 };
uintptr ilockpcs[0x100] = { [0xff] = 1 };
static int n;
void