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commit 664324745e2257289f7a61e43892ce6e8b8ed9b7
parent 4e8f237be819424f922399f8d121d9867b675541
Author: rtm <rtm>
Date:   Wed, 12 Jul 2006 09:10:25 +0000

cvs add spinlock.h
fix race in schedule()

Diffstat:
MNotes | 7+++++++
Mproc.c | 3++-
Aspinlock.h | 6++++++
Musertests.c | 4++--
4 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/Notes b/Notes @@ -126,3 +126,10 @@ in general, the table locks protect both free-ness and why can't i get a lock in console code? always triple fault lock code shouldn't call cprintf... +ide_init doesn't work now? +and IOAPIC: read from unsupported address + when running pre-empt user test + so maybe something wrong with clock interrupts + no! if one cpu holds lock w/ curproc0=, + then another cpu can take it, it looks like + a recursive acquire() diff --git a/proc.c b/proc.c @@ -148,7 +148,6 @@ scheduler(void) if(i < NPROC){ np->state = RUNNING; - release(&proc_table_lock); break; } @@ -159,6 +158,8 @@ scheduler(void) cpus[cpu()].lastproc = np; curproc[cpu()] = np; + release(&proc_table_lock); + // h/w sets busy bit in TSS descriptor sometimes, and faults // if it's set in LTR. so clear tss descriptor busy bit. np->gdt[SEG_TSS].sd_type = STS_T32A; diff --git a/spinlock.h b/spinlock.h @@ -0,0 +1,6 @@ +struct spinlock { + unsigned int locked; + struct proc *p; + int count; + unsigned locker_pc; +}; diff --git a/usertests.c b/usertests.c @@ -93,8 +93,8 @@ preempt() main() { puts("usertests starting\n"); - pipe1(); - //preempt(); + //pipe1(); + preempt(); while(1) ;