Messages in this thread | | | Date | Mon, 09 Jul 2012 08:58:38 -0600 | From | David Ahern <> | Subject | Re: perf with precise attribute kills all KVM based VMs |
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On 7/9/12 8:52 AM, David Ahern wrote: > On 7/9/12 8:49 AM, Peter Zijlstra wrote: >> On Mon, 2012-07-09 at 08:47 -0600, David Ahern wrote: >>> >>> I found this testing changes to perf-kvm, but found the problem extends >>> to just perf-record. With perf-record exclude_guest defaults to 1. See >>> tools/perf/util/util.c, event_attr_init(). >> >> You lost me there.. so perf-record defaults to exclude_guest=1 (which >> would make the proposed patch I just send actually possible), but its >> still going *bang* ? >> > > > I can do the formality of testing your proposed patch, but yes I think > so. exclude_guest defaults to 1 because perf_guest defaults to false.
Let me dig for a few minutes. exclude_user is getting reset somewhere. Setting a breakpoint on sys_perf_event_open and dumping the attribute:
$1 = {type = 0, size = 80, config = 0, {sample_period = 4000, sample_freq = 4000}, sample_type = 263, read_format = 7, disabled = 1, inherit = 1, pinned = 0, exclusive = 0, exclude_user = 0, exclude_kernel = 0, exclude_hv = 0, exclude_idle = 0, mmap = 1, comm = 1, freq = 1, inherit_stat = 0, enable_on_exec = 1, task = 0, watermark = 0, precise_ip = 1, mmap_data = 0, sample_id_all = 1, exclude_host = 0, exclude_guest = 0, __reserved_1 = 0, {wakeup_events = 0, wakeup_watermark = 0}, bp_type = 0, {bp_addr = 0, config1 = 0}, {bp_len = 0, config2 = 0}, branch_sample_type = 0}
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