| From: |
| Jon Masters <jonathan@jonmasters.org> |
| To: |
| linux-kernel@vger.kernel.org |
| Subject: |
| [PATCH 0/1] Hardware Latency Detector (formerly SMI detector) |
| Date: |
| Thu, 11 Jun 2009 00:58:29 -0400 |
| Message-ID: |
| <20090611045829.714510042@jonmasters.org> |
| Cc: |
| akpm@linux-foundation.org, tglx@linutronix.de, mingo@elte.hu,
rostedt@goodmis.org |
| Archive‑link: | |
Article |
Hi folks,
Please find attached my second re-write of the SMI detector, now called the
Hardware Latency Detector. This is a loadable module that grabs the CPU for
configurable periods of time (all under stop_machine()) and samples the TSC
looking for discontinuity. If observed latencies exceed a threshold (for
example caused by an System Management Interrupt or similar) then the
event is recorded in a global ring_buffer, readable via debugfs.
The previous version was too x86-centric, since there is no reason one could
not also use this newly renamed hwlat_detector on any supported platform with
some kind of underlying firmware/virtualization issues effecting observable
system latency measurements.
Thanks to akpm and others for feedback comments so far.
Changes since the previous version:
- Renamed to hwlat_detector
- Followed Andrew's cleanup advice
- Rewritten the documentation
Jon.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
