Messages in this thread |  | | Date | Wed, 4 Apr 2018 18:53:10 +0200 | From | Peter Zijlstra <> | Subject | Re: v4.16+ seeing many unaligned access in dequeue_task_fair() on IA64 |
| |
On Wed, Apr 04, 2018 at 09:38:56AM -0700, Luck, Tony wrote: > On Wed, Apr 04, 2018 at 09:25:13AM +0200, Peter Zijlstra wrote: > > Right, I remember being careful with that. Which again brings me to the > > RANDSTRUCT thing, which will mess that up. > > No RANDSTRUCT config options set for my build.
Weird though, with or without that patch, my ia64-defconfig gives the below layout.
$ pahole -EC sched_avg ia64-defconfig/kernel/sched/core.o die__process_function: tag not supported (INVALID)! struct sched_avg { /* typedef u64 */ long long unsigned int last_update_time; /* 0 8 */ /* typedef u64 */ long long unsigned int load_sum; /* 8 8 */ /* typedef u64 */ long long unsigned int runnable_load_sum; /* 16 8 */ /* typedef u32 */ unsigned int util_sum; /* 24 4 */ /* typedef u32 */ unsigned int period_contrib; /* 28 4 */ long unsigned int load_avg; /* 32 8 */ long unsigned int runnable_load_avg; /* 40 8 */ long unsigned int util_avg; /* 48 8 */ struct util_est { unsigned int enqueued; /* 56 4 */ unsigned int ewma; /* 60 4 */ } util_est; /* 56 8 */ /* --- cacheline 1 boundary (64 bytes) --- */
/* size: 64, cachelines: 1, members: 9 */ };
> > Does the below cure things? It makes absolutely no difference for my > > x86_64-defconfig build, but it puts more explicit alignment constraints > > on things. > > Yes. That fixes it. No unaligned traps with this patch applied. > > Tested-by: Tony Luck <tony.luck@intel.com>
Awesome, I'll go get it merged, even though I don't understand where it went wobbly.
|  |