* [9fans] minor kernel bug
@ 2014-06-05 0:56 Yoann Padioleau
2014-06-05 11:19 ` erik quanstrom
2014-06-05 11:21 ` erik quanstrom
0 siblings, 2 replies; 3+ messages in thread
From: Yoann Padioleau @ 2014-06-05 0:56 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
Hi,
Here is a patch for tasklock.c:
int
lock(Lock *l)
{
int i;
ulong pc;
pc = getcallerpc(&l);
lockstats.locks++;
if(up)
inccnt(&up->nlocks); /* prevent being scheded */
if(tas(&l->key) == 0){
if(up)
up->lastlock = l;
l->pc = pc;
l->p = up;
l->isilock = 0;
+ l->m = MACHP(m->machno);
...
return 0;
}
we do that in ilock() and canlock() so it's a bug I think to not do it also in lock().
The field is only used in iprintcanlock which use canlock(), not lock(), so this
if fine, but for consistency it would be better to also do it in lock() no?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9fans] minor kernel bug
2014-06-05 0:56 [9fans] minor kernel bug Yoann Padioleau
@ 2014-06-05 11:19 ` erik quanstrom
2014-06-05 11:21 ` erik quanstrom
1 sibling, 0 replies; 3+ messages in thread
From: erik quanstrom @ 2014-06-05 11:19 UTC (permalink / raw)
To: 9fans
> we do that in ilock() and canlock() so it's a bug I think to not do it also in lock().
> The field is only used in iprintcanlock which use canlock(), not lock(), so this
> if fine, but for consistency it would be better to also do it in lock() no?
ilock and unlock could assert(l->m->machno == m->machno). but currently
you're right on both counts.
- erik
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [9fans] minor kernel bug
2014-06-05 0:56 [9fans] minor kernel bug Yoann Padioleau
2014-06-05 11:19 ` erik quanstrom
@ 2014-06-05 11:21 ` erik quanstrom
1 sibling, 0 replies; 3+ messages in thread
From: erik quanstrom @ 2014-06-05 11:21 UTC (permalink / raw)
To: 9fans
oh, but you missed a spot in lock.
- erik
^ permalink raw reply [flat|nested] 3+ messages in thread
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2014-06-05 0:56 [9fans] minor kernel bug Yoann Padioleau
2014-06-05 11:19 ` erik quanstrom
2014-06-05 11:21 ` erik quanstrom
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