Commit 360b6e5c authored by Randy Dunlap's avatar Randy Dunlap Committed by Ingo Molnar
Browse files

Documentation: Update mmiotrace.txt



Fix typos, spellos, hyphenation, line lengths.

BTW:  are there some userspace tools?  There is a reference to
some at the wiki page, but there are no tools listed there.
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Acked-by: default avatarPekka Paalanen <pq@iki.fi>
LKML-Reference: <4B2C0D68.6080401@oracle.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent e36c5458
......@@ -44,7 +44,8 @@ Check for lost events.
Usage
-----
Make sure debugfs is mounted to /sys/kernel/debug. If not, (requires root privileges)
Make sure debugfs is mounted to /sys/kernel/debug.
If not (requires root privileges):
$ mount -t debugfs debugfs /sys/kernel/debug
Check that the driver you are about to trace is not loaded.
......@@ -91,7 +92,7 @@ $ dmesg > dmesg.txt
$ tar zcf pciid-nick-mmiotrace.tar.gz mydump.txt lspci.txt dmesg.txt
and then send the .tar.gz file. The trace compresses considerably. Replace
"pciid" and "nick" with the PCI ID or model name of your piece of hardware
under investigation and your nick name.
under investigation and your nickname.
How Mmiotrace Works
......@@ -100,7 +101,7 @@ How Mmiotrace Works
Access to hardware IO-memory is gained by mapping addresses from PCI bus by
calling one of the ioremap_*() functions. Mmiotrace is hooked into the
__ioremap() function and gets called whenever a mapping is created. Mapping is
an event that is recorded into the trace log. Note, that ISA range mappings
an event that is recorded into the trace log. Note that ISA range mappings
are not caught, since the mapping always exists and is returned directly.
MMIO accesses are recorded via page faults. Just before __ioremap() returns,
......@@ -122,11 +123,11 @@ Trace Log Format
----------------
The raw log is text and easily filtered with e.g. grep and awk. One record is
one line in the log. A record starts with a keyword, followed by keyword
dependant arguments. Arguments are separated by a space, or continue until the
one line in the log. A record starts with a keyword, followed by keyword-
dependent arguments. Arguments are separated by a space, or continue until the
end of line. The format for version 20070824 is as follows:
Explanation Keyword Space separated arguments
Explanation Keyword Space-separated arguments
---------------------------------------------------------------------------
read event R width, timestamp, map id, physical, value, PC, PID
......@@ -136,7 +137,7 @@ iounmap event UNMAP timestamp, map id, PC, PID
marker MARK timestamp, text
version VERSION the string "20070824"
info for reader LSPCI one line from lspci -v
PCI address map PCIDEV space separated /proc/bus/pci/devices data
PCI address map PCIDEV space-separated /proc/bus/pci/devices data
unk. opcode UNKNOWN timestamp, map id, physical, data, PC, PID
Timestamp is in seconds with decimals. Physical is a PCI bus address, virtual
......
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