diff options
Diffstat (limited to 'Documentation/trace/mmiotrace.txt')
| -rw-r--r-- | Documentation/trace/mmiotrace.txt | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/Documentation/trace/mmiotrace.txt b/Documentation/trace/mmiotrace.txt index 162effb..664e738 100644 --- a/Documentation/trace/mmiotrace.txt +++ b/Documentation/trace/mmiotrace.txt @@ -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 |