Messages in this thread | | | Date | Tue, 1 Apr 2003 15:13:58 -0800 (PST) | From | Linus Torvalds <> | Subject | Re: [BUG] 2.5.65: Caching MSR_IA32_SYSENTER_CS kills dosemu |
| |
On 1 Apr 2003, Robert Love wrote: > > Actually, do they do disable preemption - if they do not, something is > broken.
Ok, I was too lazy to check. Anyway, the test-patch is worth trying, since one of the areas fixed had no pre-emption protection regardless (ie it used just a plain "smp_processor_id()"), and the patch should be technically equivalent (just uglier) to a proper get_cpu().
> Because, even on UP, preemption can lead to a race over a variable that > has no locking because its per-CPU. But it would need locking > otherwise, and thus we do need to disable preemption.
Yes, that was certainly the case here.
Linus
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |