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Diffstat (limited to 'Documentation/dynamic-debug-howto.txt')
| -rw-r--r-- | Documentation/dynamic-debug-howto.txt | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt index 6e1684981da..72322c6d735 100644 --- a/Documentation/dynamic-debug-howto.txt +++ b/Documentation/dynamic-debug-howto.txt @@ -6,8 +6,16 @@ This document describes how to use the dynamic debug (dyndbg) feature. Dynamic debug is designed to allow you to dynamically enable/disable kernel code to obtain additional kernel information. Currently, if -CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() calls can -be dynamically enabled per-callsite. +CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_dbg() and +print_hex_dump_debug()/print_hex_dump_bytes() calls can be dynamically +enabled per-callsite. + +If CONFIG_DYNAMIC_DEBUG is not set, print_hex_dump_debug() is just +shortcut for print_hex_dump(KERN_DEBUG). + +For print_hex_dump_debug()/print_hex_dump_bytes(), format string is +its 'prefix_str' argument, if it is constant string; or "hexdump" +in case 'prefix_str' is build dynamically. Dynamic debug has even more useful features: @@ -202,6 +210,9 @@ The flags are: t Include thread ID in messages not generated from interrupt context _ No flags are set. (Or'd with others on input) +For print_hex_dump_debug() and print_hex_dump_bytes(), only 'p' flag +have meaning, other flags ignored. + For display, the flags are preceded by '=' (mnemonic: what the flags are currently equal to). |