The Alignment Fault Utility (FLT) finds alignment faults and records them in a ring buffer, which can be sized when starting alignment fault tracing. The summary screen displays the results sorted by the program counter (PC) that has incurred the most alignment faults. The detailed trace output also shows the process identification (PID) of the process that caused the alignment fault, with the virtual address that triggered the fault.

Output can be directed to a file using the SDA SET OUTPUT command.

FLT can be started and stopped as required without the need for a system reboot.

6.1 FLT Commands

Table 6-1 summarizes the commands for the FLT utility.

Table 6-1 Commands for the Alignment Fault Utility

Commands	Description
FLT LOAD	Loads the FLT$DEBUG execlet.
FLT UNLOAD	Unloads the FLT$DEBUG execlet.
FLT START TRACE	Starts alignment fault tracing.
FLT	Lists the FLT commands.
FLT STOP TRACE	Stops tracing.
FLT SHOW TRACE	Displays detailed information about the trace.

The end of this chapter has an example of how you might use these FLT commands.

When entered with no keywords, lists the FLT commands.

Format

FLT

Parameters

None.

Qualifiers

None.

Loads the FLT$DEBUG execlet. Do this before starting alignment fault tracing.

Format

FLT LOAD

Parameters

None.

Qualifiers

None.

Displays detail about the trace.

Format

FLT SHOW TRACE [/SUMMARY [/RATES (d) | /TOTALS]]

Parameters

None.

Qualifiers

/RATES

When used with /SUMMARY, the alignment fault rate per second for each PC during the collection interval is displayed. This is the default.

/SUMMARY

Displays the results sorted by the program counter (PC) that has incurred the most alignment faults.

/TOTALS

When used with /SUMMARY, the total number of alignment faults for each PC during the collection interval is displayed.

Starts alignment fault tracing. By default, all PCs are traced.

Format

START TRACE [/BUFFER=pages] [/BEGIN=pc_range_low]
[/CALLER] [/END=pc_range_high]
[/INDEX=pid] [MODE=(mode,...)]

Parameters

None.

Qualifiers

/BUFFER=pages

The number of pages to size the trace buffer. The default is 128 pages or 1MB.

/BEGIN=pc_range_low

Start of range of PCs to trace.

/CALLER

For each alignment fault, in addition to recording the PC that incurred the fault, FLT also records the PCs of the caller, the callers caller, and so on, for up to 10 call frames.

/END=pc_range_high

End of range of PCs to trace.

/INDEX=pid

Only trace alignment faults for the specified process. You can specify the process index itself, or the process identification or extended process identification, from which the process index is extracted.

/MODE=(mode,...)

Only trace alignment faults that occur in the specified modes. Allowed modes are KERNEL, EXEC, SUPER and USER. If you specify only one mode, you can omit the parentheses.

Stops tracing.

Format

FLT STOP TRACE

Parameters

None.

Qualifiers

None.

Unloads the FLT$DEBUG execlet.

Format

FLT UNLOAD

Parameters

None.

Qualifiers

None.

Example 6-1 Example

SDA> flt load SDA> flt start trace . . . SDA> flt show trace /summary Fault Trace Information: (at 12-OCT-2004 16:09:29.43, trace time 00:00:55.145335) --------------------------------------------------------------------------------- Exception PC Count Exception PC Module Offset ----------------- ------------ -------------------------------------- ---------------------------------- FFFFFFFF.86214790 973 RDMSHRP72+0019E790 RDMSHRP72 0019E790 FFFFFFFF.86214791 871 RDMSHRP72+0019E791 RDMSHRP72 0019E791 FFFFFFFF.8620B261 700 RDMSHRP72+00195261 RDMSHRP72 00195261 FFFFFFFF.8620B260 700 RDMSHRP72+00195260 RDMSHRP72 00195260 FFFFFFFF.841C3451 208 LIBRTL+00195451 LIBRTL 00195451 FFFFFFFF.818E43E0 193 NET$TRANSPORT_NSP+303E0 NET$TRANSPORT_NSP 000303E0 FFFFFFFF.818E4400 193 NET$TRANSPORT_NSP+30400 NET$TRANSPORT_NSP 00030400 FFFFFFFF.818E4430 193 NET$TRANSPORT_NSP+30430 NET$TRANSPORT_NSP 00030430 FFFFFFFF.818E4450 193 NET$TRANSPORT_NSP+30450 NET$TRANSPORT_NSP 00030450 FFFFFFFF.818E44B1 193 NET$TRANSPORT_NSP+304B1 NET$TRANSPORT_NSP 000304B1 FFFFFFFF.818E44D0 193 NET$TRANSPORT_NSP+304D0 NET$TRANSPORT_NSP 000304D0 FFFFFFFF.818E6720 186 NET$TRANSPORT_NSP+32720 NET$TRANSPORT_NSP 00032720 FFFFFFFF.818E64C0 179 NET$TRANSPORT_NSP+324C0 NET$TRANSPORT_NSP 000324C0 FFFFFFFF.818E6520 179 NET$TRANSPORT_NSP+32520 NET$TRANSPORT_NSP 00032520 FFFFFFFF.86DE9480 166 RDMSHRP72+00D73480 RDMSHRP72 00D73480 FFFFFFFF.807814A1 162 EXE$SETOPR_C+00841 MESSAGE_ROUTINES 0001D7A1 FFFFFFFF.86DE8C90 146 RDMSHRP72+00D72C90 RDMSHRP72 00D72C90 FFFFFFFF.86DE8EC0 146 RDMSHRP72+00D72EC0 RDMSHRP72 00D72EC0 FFFFFFFF.8701C340 146 RDMSHRP72+00FA6340 RDMSHRP72 00FA6340 FFFFFFFF.862026E1 100 RDMSHRP72+0018C6E1 RDMSHRP72 0018C6E1 FFFFFFFF.86202580 100 RDMSHRP72+0018C580 RDMSHRP72 0018C580 FFFFFFFF.862025B0 100 RDMSHRP72+0018C5B0 RDMSHRP72 0018C5B0 FFFFFFFF.8701B900 83 RDMSHRP72+00FA5900 RDMSHRP72 00FA5900 00000000.000EE990 37 00000000.000EEA51 37 00000000.000EE8D1 37 FFFFFFFF.807359C1 28 LOCKING+253C1 LOCKING 000253C1 FFFFFFFF.807359F1 28 LOCKING+253F1 LOCKING 000253F1 FFFFFFFF.80732EE0 27 LCK$FILL_RSB_CACHE_C+008F0 LOCKING 000228E0 FFFFFFFF.86DE8690 18 RDMSHRP72+00D72690 RDMSHRP72 00D72690 FFFFFFFF.80B388A0 15 SECURITY+461A0 SECURITY 000461A0 FFFFFFFF.80B213F0 13 NSA$SIZE_NSAB_C+00840 SECURITY 0002ECF0 FFFFFFFF.86DFE9E0 12 RDMSHRP72+00D889E0 RDMSHRP72 00D889E0 [...............] SDA> flt show trace Unaligned Data Fault Trace Information: --------------------------------------- Timestamp CPU Unaligned VA Exception PC Access EPID Trace Buffer ---------------------- --- ----------------- -------------------------------------- -------- -------- ----------------- 12-OCT 16:09:56.439499 02 00000000.014A4F8A 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.74921610 12-OCT 16:09:56.439493 02 00000000.023DFFD4 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749215E8 12-OCT 16:09:56.439486 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749215C0 12-OCT 16:09:56.439480 02 00000000.014A4F8A 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921598 12-OCT 16:09:56.439254 02 00000000.0154F1DC 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.74921570 12-OCT 16:09:56.431606 02 00000000.014A4F5A 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.74921548 12-OCT 16:09:56.431601 02 00000000.022DEE44 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921520 12-OCT 16:09:56.431594 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749214F8 12-OCT 16:09:56.431588 02 00000000.014A4F5A 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749214D0 12-OCT 16:09:56.430255 02 00000000.0155BDDC 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.749214A8 12-OCT 16:09:56.426878 02 00000000.014A4F72 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.74921480 12-OCT 16:09:56.426872 02 00000000.02394ED4 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921458 12-OCT 16:09:56.426865 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921430 12-OCT 16:09:56.426859 02 00000000.014A4F72 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921408 12-OCT 16:09:56.426583 02 00000000.0154A97C 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.749213E0 12-OCT 16:09:56.421244 02 00000000.014A4F52 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.749213B8 12-OCT 16:09:56.421238 02 00000000.02296824 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921390 12-OCT 16:09:56.421232 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921368 12-OCT 16:09:56.421226 02 00000000.014A4F52 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921340 12-OCT 16:09:56.420916 02 00000000.0156405C 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.74921318 12-OCT 16:09:56.413932 02 00000000.014A4F52 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.749212F0 12-OCT 16:09:56.413926 02 00000000.023C10D4 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749212C8 12-OCT 16:09:56.413918 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749212A0 12-OCT 16:09:56.413913 02 00000000.014A4F52 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921278 12-OCT 16:09:56.413645 02 00000000.01564E9C 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.74921250 12-OCT 16:09:56.403972 02 00000000.014A4F52 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.74921228 12-OCT 16:09:56.403966 02 00000000.023036C4 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921200 12-OCT 16:09:56.403960 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749211D8 12-OCT 16:09:56.403954 02 00000000.014A4F52 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.749211B0 12-OCT 16:09:56.403689 02 00000000.0155E47C 807814A1 EXE$SETOPR_C+00841 Exec 39C004DC FFFFFFFF.74921188 12-OCT 16:09:56.395575 02 00000000.014A4F8A 86214791 RDMSHRP72+0019E791 Exec 39C004DC FFFFFFFF.74921160 12-OCT 16:09:56.395569 02 00000000.02448D24 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921138 12-OCT 16:09:56.395562 02 00000000.014A4F42 86214790 RDMSHRP72+0019E790 Exec 39C004DC FFFFFFFF.74921110 [....................]