On Wed, Oct 19, 2022 at 10:44 PM Sedat Dilek (DHL Supply Chain) <sedat.dilek@xxxxxxx> wrote: > > -----Ursprüngliche Nachricht----- > Von: Sami Tolvanen <samitolvanen@xxxxxxxxxx> > Gesendet: Dienstag, 18. Oktober 2022 18:00 > An: Sedat Dilek (DHL Supply Chain) <sedat.dilek@xxxxxxx> > Betreff: Re: Update15.x/kcfi to LLVM 15.0.3 > > On Tue, Oct 18, 2022 at 4:54 AM Sedat Dilek (DHL Supply Chain) <sedat.dilek@xxxxxxx> wrote: > > > [ CC Nick + Fangrui ] > > You happen to know or use the ZSTD cmake-option (see [1] and [2]) - came in with changes post-15.0.2? > > AFAICS Fangrui Song had some patches to use ZSTD debug-compression with DWARFv5. > > Unsure, if that combination is now possible in v15.0.3 or is a feature of LLVM-16. > > [3] says: > > [ lib/Kconfig.debug ] > > config DEBUG_INFO_COMPRESSED > bool "Compressed debugging information" > depends on $(cc-option,-gz=zlib) > depends on $(ld-option,--compress-debug-sections=zlib) > help > Compress the debug information using zlib. Requires GCC 5.0+ or Clang > 5.0+, binutils 2.26+, and zlib. > > Users of dpkg-deb via scripts/package/builddeb may find an increase in > size of their debug .deb packages with this config set, due to the > debug info being compressed with zlib, then the object files being > recompressed with a different compression scheme. But this is still > preferable to setting $KDEB_COMPRESS to "none" which would be even > larger. > > I am interested in the equivalent changes to cc-option/ld-option with ZSTD (usable with DWARFv5). Good idea. It looks like there's still a blocker to using -gz=zstd with clang: $ clang -gz=zstd -x c - < /dev/null clang-16: warning: cannot compress debug sections (zstd not enabled) [-Wdebug-compression-unavailable] https://github.com/facebook/zstd/issues/3271 Attaching a WIP patch. > > Thanks. > > Best regards, > -Sedat- > > [1] https://github.com/llvm/llvm-project/commit/6fba7854a2f0b6b3899bb156c1a0c4ae35c96e24 > [2] https://github.com/llvm/llvm-project/commit/b4840279846e1eea44c3dca575395a90c9d77ca0 > [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/Kconfig.debug#n315 > [4] https://metadata.ftp-master.debian.org/changelogs//main/l/llvm-toolchain-15/llvm-toolchain-15_15.0.3-1~exp1_changelog > > > -- Thanks, ~Nick Desaulniers
From c9ccf84c1a3fc742123dcc6b7789206506190260 Mon Sep 17 00:00:00 2001 From: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Date: Thu, 20 Oct 2022 09:54:22 -0700 Subject: [PATCH] WIP: Makefile.debug: support for -gz=zstd Make DEBUG_INFO_COMPRESSED a choice; DEBUG_INFO_UNCOMPRESSED is the default, DEBUG_INFO_COMPRESSED uses zlib, DEBUG_INFO_COMPRESSED_ZSTD uses zstd. TODO: measurements 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
