[PATCH 00/22] various dynamic_debug patches

Rasmus Villemoes
2018-09-19T22:04:22Z

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

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2.16.4