On Tue, 26 Jul 2022 19:01:47 -0700 Beau Belgrave <beaub@xxxxxxxxxxxxxxxxxxx> wrote: > Ah, I see the confusion. Sorry. > > EVENT_STATUS_* are internal bits that aren't used with STATUS_MASK or > STATUS_BYTE. It's only used to set and check the user event status byte > for checking if anything is attached and outputting which probe is > connected within the kernel side. > > STATUS_BYTE and STATUS_MASK take a bit in a bitmap and figure out which > byte in the status mapping should be used and which bit in that byte > should be set/reset (mask) when it's enabled/disabled via a probe. Both > the user and kernel need to align on this logic. > > IE: Bits above the lower 3 of the index/bit of the event to enable is the byte > and the lower 3 bits (& 7) is the actual bit to set. > > For example if the user_event with the index 1024 is enabled, we need to > figure out which byte and bit represents that event when a probe is > attached. > > I got into detail of this in the documentation for both a byte and long > wise checking of these values. > > Hope that helps explain it. Yes, but that should be in the comments above the code. -- Steve
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