This started as an experiment to see how hard it would be to change the four pointers in struct _ddebug into relative offsets, a la CONFIG_GENERIC_BUG_RELATIVE_POINTERS, thus saving 16 bytes per pr_debug site (and thus exactly making up for the extra space used by the introduction of jump labels in 9049fc74). I stumbled on a few things that are probably worth fixing regardless of whether the latter half of this series is deemed worthwhile. Patch relationships: 1-2, 3-4, 5-6 and 15-16 can be applied individually, though 2, 4 and 6 probably makes most sense in the context of the final goal of the series. 7-12 I believe make sense on their own. Patch 13 again only makes sense if we go all the way, and 14 and 17 depend on 13. 18-21 are more preparatory patches, and finally 22 switch over x86-64 to use CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS. I've tested that the end result boots under virtme and that the dynamic_debug control file has the expected contents. Rasmus Villemoes (22): linux/device.h: use DYNAMIC_DEBUG_BRANCH in dev_dbg_ratelimited linux/device.h: use unique identifier for each struct _ddebug linux/net.h: use DYNAMIC_DEBUG_BRANCH in net_dbg_ratelimited linux/net.h: use unique identifier for each struct _ddebug linux/printk.h: use DYNAMIC_DEBUG_BRANCH in pr_debug_ratelimited linux/printk.h: use unique identifier for each struct _ddebug dynamic_debug: consolidate DEFINE_DYNAMIC_DEBUG_METADATA definitions dynamic_debug: don't duplicate modname in ddebug_add_module dynamic_debug: use pointer comparison in ddebug_remove_module dynamic_debug: remove unused EXPORT_SYMBOLs dynamic_debug: move pr_err from module.c to ddebug_add_module dynamic_debug: add static inline stub for ddebug_add_module dynamic_debug: refactor dynamic_pr_debug and friends btrfs: implement btrfs_debug* in terms of helper macro ACPI: use proper DYNAMIC_DEBUG_BRANCH macro ACPI: remove unused __acpi_handle_debug macro ACPI: implement acpi_handle_debug in terms of _dynamic_func_call dynamic_debug: introduce accessors for string members of struct _ddebug dynamic_debug: drop use of bitfields in struct _ddebug dynamic_debug: introduce CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS x86: jump_label: introduce ASM_STATIC_KEY_INIT_{TRUE,FALSE} x86_64: use relative pointers with dynamic debug arch/x86/Kconfig | 1 + arch/x86/include/asm/dynamic_debug.h | 35 +++++++++ arch/x86/include/asm/jump_label.h | 18 +++++ fs/btrfs/ctree.h | 34 +++------ include/linux/acpi.h | 11 +-- include/linux/device.h | 6 +- include/linux/dynamic_debug.h | 126 +++++++++++++++++++-------------- include/linux/jump_label.h | 2 + include/linux/net.h | 6 +- include/linux/printk.h | 6 +- kernel/module.c | 6 +- lib/Kconfig.debug | 3 + lib/dynamic_debug.c | 133 ++++++++++++++++++++++++----------- 13 files changed, 251 insertions(+), 136 deletions(-) create mode 100644 arch/x86/include/asm/dynamic_debug.h -- 2.16.4