From: "Luck, Tony" <tony.luck@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: "x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] RAS: Fix the trace_show() function to output trace_count
Date: Mon, 17 Oct 2022 16:09:23 +0000 [thread overview]
Message-ID: <SJ1PR11MB60835DDCB1F3EBC8B6DFA2F7FC299@SJ1PR11MB6083.namprd11.prod.outlook.com> (raw)
In-Reply-To: <Y00wIFEN9h9YPGe1@zn.tnic>
> Still misleading:
>
> $ cat /sys/kernel/debug/ras/daemon_active
> 1
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).
> I don't know, maybe we should teach RAS daemons to ->write() into that
> file their name and PID so that the trace_count counts *only* the RAS
> daemons not any reader...
Should have thought of this earlier ... changing user space semantics
is hard. Even with only one user, there is a long transition period where
new kernels are running with old rasdaemon and vice versa.
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?
-Tony
next prev parent reply other threads:[~2022-10-17 16:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-05 16:16 [PATCH] RAS: Fix the trace_show() function to output trace_count Tony Luck
2022-10-05 18:17 ` Borislav Petkov
2022-10-05 19:46 ` [PATCH v2] " Tony Luck
2022-10-17 10:36 ` Borislav Petkov
2022-10-17 16:09 ` Luck, Tony [this message]
2022-10-17 19:40 ` Borislav Petkov
2022-10-18 14:36 ` Tony Luck
2022-10-18 16:05 ` Borislav Petkov
2022-10-18 16:59 ` [PATCH v3] RAS: Fix return value from show_trace() Tony Luck
2022-10-31 18:15 ` [tip: ras/core] " tip-bot2 for Tony Luck
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