On 06.09.12 13:17:19, David Ahern wrote: > On 9/6/12 1:02 PM, Robert Richter wrote: > > just found your patch...
I tested the patch and it runs ok with my kernel patch that checks syscall attributes for ibs. perf tools falls back and clears exclude_guest/_host bits in attr. It also should work if the kernel ignores those bits (without my patch). Acked-by: Robert Richter <robert.rich...@amd.com> > > To summarize how I think it should work: > > > > -e cycles:p ..... Enable exclude_guest bit. If the syscall fails, > > fall back by disabling the guest bit and send > > syscall again > > I think the fallback scenarios are getting out of hand -- too many and > too many combinations. For this case (:p only) I proposed setting > exclude_guest. It should not fail if the pebs/ibs is supported. If so, > give the user a helpful message. e.g., https://lkml.org/lkml/2012/7/20/440 > > > > > > -e cycles:pGH ... Do not enable exclude_guest/_host. Do not fall back > > on syscall errors. > > In this case give the user a message that the requested combination is > invalid. I have a patch similar to the one above for this. Yes, but cases where only guest or host-only mode is supported are rare. > > > > > Same for the case the p modifier is not set. > > > > So we have the following: > > > > G ... set exclude_host bit, clear exclude_guest > > H ... set exclude_guest bit, clear exclude_host > > GH ... clear both exclude_guest/_host > > <no G or H> ... default (set exclude_host bit, clear exclude_guest), > > but fall back on syscall errors to clear both > > exclude_guest/_host > > you lost me on the last one. If the user specifies no attributes on the > events then exclude_host/exclude_guest is controlled by the > perf_host/perf_guest variables - see event_attr_init(). As you said above, falling back by disabling flags becomes unhandy. Current implementation falls back without (?) notice even if the user explicitly demanded G or H. Falling back should only be the case if no G/H modifiers are given. This is what I meant here. > > The modifier parser should be correctly implemented and should work > > with ibs. Will test this patch. > > Thanks! Sorry far being late a bit with all this. -Robert -- Advanced Micro Devices, Inc. Operating System Research Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
