Messages in this thread | | | Date | Mon, 17 Oct 2022 21:40:09 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v2] RAS: Fix the trace_show() function to output trace_count |
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On Mon, Oct 17, 2022 at 04:09:23PM +0000, Luck, Tony wrote: > Agreed. It needs user to interpret the answer. The filename would lead > them to think "1" means the daemon is active, but its actually just a count > of how many times the file is concurrently open (which includes the > "cat" process reading the file).
Yap, exactly.
> Should have thought of this earlier ... changing user space semantics > is hard.
AFAIR, at the time we cared only about there being at least one consumer... thus the binary test, is there at least one or not:
if (!ras_userspace_consumers()) { print_extlog_rcd(NULL, tmp, cpu); goto out; }
> How about: > > seq_printf(m, "%d\n", atomic_read(&trace_count) - 1); > > with a comment that users reading the file only want to know if anyone > else has it open?
Yeah, doesn't work either:
# tail -f /sys/kernel/debug/ras/daemon_active & [1] 3019 1 tail: /sys/kernel/debug/ras/daemon_active: file truncated 1 # cat /sys/kernel/debug/ras/daemon_active 2
We really need something to say, "I really am a RAS events consumer and not some random file opener."
OTOH, if one does that on ones system, then one has herself to blame when errors don't get logged and disappear. I mean, why would one even do that?!
Then again, I've seen weirder stuff so...
Question is, what is your goal with this?
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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