On Mon, 2007-07-23 at 18:32 +0200, Peter Zijlstra wrote: > On Mon, 2007-07-23 at 08:21 -0700, Daniel Walker wrote: > > Resolves, > > > > BUG: sleeping function called from invalid context cc1(29651) at kernel/rtmutex.c:636 > > in_atomic():1 [00000001], irqs_disabled():0 > > [<c0119f50>] __might_sleep+0xf3/0xf9 > > [<c031600e>] __rt_spin_lock+0x21/0x3c > > [<c014102c>] get_zone_pcp+0x20/0x29 > > [<c0141a40>] free_hot_cold_page+0xdc/0x167 > > [<c013a3f4>] add_preempt_count+0x12/0xcc > > [<c0110d92>] pgd_dtor+0x0/0x1 > > [<c015d865>] quicklist_trim+0xb7/0xe3 > > [<c0111025>] check_pgt_cache+0x19/0x1c > > [<c0148df5>] free_pgtables+0x54/0x12c > > [<c013a3f4>] add_preempt_count+0x12/0xcc > > [<c014e5be>] unmap_region+0xeb/0x13b > > > > > > It looks like the quicklist isn't used after a few variables are evaluated. > > So no need to keep preemption disabled over the whole function. > > Not quite, it uses preempt_disable() to avoid migration and stick to a > cpu. Without that it might end up freeing pages from another quicklist. > > How about this - compile tested only How about a comment to go with it ? Which says something like what's above, notes on how the locking is getting used.. Daniel - To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
