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add _procwakeupandunlock

Browse source 
to help ease locking contention
on Linux 2.4.
This commit is contained in:
rsc 2005-01-06 23:43:42 +00:00
parent 815552b9ed
commit a0a331aad9
5 changed files with 44 additions and 12 deletions
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27
src/libthread/Linux.c
View file

@ -32,7 +32,7 @@ _threadlock(Lock *l, int block, ulong pc)
{
int i;
static int first=1;
if(first) {first=0; fmtinstall('T', timefmt);}
if(first) {first=0; fmtinstall('\001', timefmt);}
USED(pc);
@ -48,43 +48,43 @@ if(first) {first=0; fmtinstall('T', timefmt);}
return 1;
sched_yield();
}
/* now nice and slow */
/* now increasingly slow */
for(i=0; i<10; i++){
if(!_tas(&l->held))
return 1;
usleep(1);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop1 %p from %lux\n", argv0, l, pc);
for(i=0; i<10; i++){
if(!_tas(&l->held))
return 1;
usleep(10);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop2 %p from %lux\n", argv0, l, pc);
for(i=0; i<10; i++){
if(!_tas(&l->held))
return 1;
usleep(100);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop3 %p from %lux\n", argv0, l, pc);
for(i=0; i<10; i++){
if(!_tas(&l->held))
return 1;
usleep(1000);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop4 %p from %lux\n", argv0, l, pc);
for(i=0; i<10; i++){
if(!_tas(&l->held))
return 1;
usleep(10*1000);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop5 %p from %lux\n", argv0, l, pc);
for(i=0; i<1000; i++){
if(!_tas(&l->held))
return 1;
usleep(100*1000);
}
fprint(2, "%T lock loop %p from %lux\n", l, pc);
fprint(2, "%\001 %s: lock loop6 %p from %lux\n", argv0, l, pc);
/* take your time */
while(_tas(&l->held))
usleep(1000*1000);
@ -150,13 +150,20 @@ again:
}
void
_procwakeup(_Procrendez *r)
_procwakeupandunlock(_Procrendez *r)
{
int pid;
pid = 0;
if(r->asleep){
r->asleep = 0;
assert(r->pid >= 1);
kill(r->pid, SIGUSR1);
pid = r->pid;
}
assert(r->l);
unlock(r->l);
if(pid)
kill(pid, SIGUSR1);
}
/*