Make DEBUG_INFO_COMPRESSED a choice; DEBUG_INFO_UNCOMPRESSED is the default, DEBUG_INFO_COMPRESSED uses zlib, DEBUG_INFO_COMPRESSED_ZSTD uses zstd. Some quick N=1 measurements with du, /usr/bin/time -v, and bloaty: clang-16, x86_64 defconfig plus CONFIG_DEBUG_INFO=y CONFIG_DEBUG_INFO_UNCOMPRESSED=y: Elapsed (wall clock) time (h:mm:ss or m:ss): 0:55.43 488M vmlinux 27.6% 136Mi 0.0% 0 .debug_info 6.1% 30.2Mi 0.0% 0 .debug_str_offsets 3.5% 17.2Mi 0.0% 0 .debug_line 3.3% 16.3Mi 0.0% 0 .debug_loclists 0.9% 4.62Mi 0.0% 0 .debug_str clang-16, x86_64 defconfig plus CONFIG_DEBUG_INFO=y CONFIG_DEBUG_INFO_COMPRESSED=y (zlib): Elapsed (wall clock) time (h:mm:ss or m:ss): 1:00.35 385M vmlinux 21.8% 85.4Mi 0.0% 0 .debug_info 2.1% 8.26Mi 0.0% 0 .debug_str_offsets 2.1% 8.24Mi 0.0% 0 .debug_loclists 1.9% 7.48Mi 0.0% 0 .debug_line 0.5% 1.94Mi 0.0% 0 .debug_str clang-16, x86_64 defconfig plus CONFIG_DEBUG_INFO=y CONFIG_DEBUG_INFO_COMPRESSED_ZSTD=y (zstd): Elapsed (wall clock) time (h:mm:ss or m:ss): 0:59.69 373M vmlinux 21.4% 81.4Mi 0.0% 0 .debug_info 2.3% 8.85Mi 0.0% 0 .debug_loclists 1.5% 5.71Mi 0.0% 0 .debug_line 0.5% 1.95Mi 0.0% 0 .debug_str_offsets 0.4% 1.62Mi 0.0% 0 .debug_str That's only a 3.11% overall binary size savings over zlib, but at no performance regression. Link: https://maskray.me/blog/2022-09-09-zstd-compressed-debug-sections Link: https://maskray.me/blog/2022-01-23-compressed-debug-sections Suggested-by: Sedat Dilek (DHL Supply Chain) <sedat.dilek@xxxxxxx> Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> --- lib/Kconfig.debug | 26 +++++++++++++++++++++++++- scripts/Makefile.debug | 4 ++++ 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 3fc7abffc7aa..4085ac77dc12 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -312,8 +312,22 @@ config DEBUG_INFO_REDUCED DEBUG_INFO build and compile times are reduced too. Only works with newer gcc versions. +choice + prompt "Compressed Debug information" + depends on DEBUG_KERNEL + help + Compress the resulting debug info. Results in smaller debug info sections, + but requires that consumers are able to decompress the results. + + If unsure, choose DEBUG_INFO_UNCOMPRESSED. + +config DEBUG_INFO_UNCOMPRESSED + bool "Don't compress debug information" + help + Don't compress debug info sections. + config DEBUG_INFO_COMPRESSED - bool "Compressed debugging information" + bool "Compress debugging information with zlib" depends on $(cc-option,-gz=zlib) depends on $(ld-option,--compress-debug-sections=zlib) help @@ -327,6 +341,16 @@ config DEBUG_INFO_COMPRESSED preferable to setting $KDEB_COMPRESS to "none" which would be even larger. +config DEBUG_INFO_COMPRESSED_ZSTD + bool "Compress debugging information with zstd" + depends on $(cc-option,-gz=zstd) + depends on $(ld-option,--compress-debug-sections=zstd) + help + Compress the debug information using zstd. Requires GCC 13.0+ or Clang + 16.0+, binutils 2.40+, and zstd. + +endchoice # "Compressed Debug information" + config DEBUG_INFO_SPLIT bool "Produce split debuginfo in .dwo files" depends on $(cc-option,-gsplit-dwarf) diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug index 332c486f705f..8ac3379d2255 100644 --- a/scripts/Makefile.debug +++ b/scripts/Makefile.debug @@ -31,6 +31,10 @@ ifdef CONFIG_DEBUG_INFO_COMPRESSED DEBUG_CFLAGS += -gz=zlib KBUILD_AFLAGS += -gz=zlib KBUILD_LDFLAGS += --compress-debug-sections=zlib +else ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZSTD +DEBUG_CFLAGS += -gz=zstd +KBUILD_AFLAGS += -gz=zstd +KBUILD_LDFLAGS += --compress-debug-sections=zstd endif KBUILD_CFLAGS += $(DEBUG_CFLAGS) -- 2.38.0.135.g90850a2211-goog
