Messages in this thread | | | Date | Wed, 22 Jun 2022 16:56:05 +1000 | Subject | Re: [PATCH kernel v2] zstd: Fixing mixed module-builtin objects | From | Alexey Kardashevskiy <> |
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Ping? It's about 2 months now :)
On 6/6/22 15:12, Alexey Kardashevskiy wrote: > Ping? > > > On 5/17/22 09:52, Nathan Chancellor wrote: >> Hi Nick, >> >> Did you have any thoughts on this patch? It is necessary for enabling >> LTO with PowerPC: >> >> https://lore.kernel.org/20220429064547.2334280-1-aik@ozlabs.ru/ >> >> If you don't have anything to send to Linus for the next cycle, perhaps >> this patch could be carried by the PowerPC folks with your ack? >> >> Cheers, >> Nathan >> >> On Fri, Apr 29, 2022 at 03:33:29PM +1000, Alexey Kardashevskiy wrote: >>> With CONFIG_ZSTD_COMPRESS=m and CONFIG_ZSTD_DECOMPRESS=y we end up in >>> a situation when files from lib/zstd/common/ are compiled once to be >>> linked later for ZSTD_DECOMPRESS (build-in) and ZSTD_COMPRESS (module) >>> even though CFLAGS are different for builtins and modules. >>> So far somehow this was not a problem but enabling LLVM LTO exposes >>> the problem as: >>> >>> ld.lld: error: linking module flags 'Code Model': IDs have >>> conflicting values in 'lib/built-in.a(zstd_common.o at 5868)' and >>> 'ld-temp.o' >>> >>> This particular conflict is caused by KBUILD_CFLAGS=-mcmodel=medium vs. >>> KBUILD_CFLAGS_MODULE=-mcmodel=large , modules use the large model on >>> POWERPC as explained at >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/powerpc/Makefile?h=v5.18-rc4#n127 >>> but the current use of common files is wrong anyway. >>> >>> This works around the issue by introducing a zstd_common module with >>> shared code. >>> >>> Cc: Masahiro Yamada <masahiroy@kernel.org> >>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> >>> --- >>> Changes: >>> v2: >>> * add a new module instead of inlining common bits >>> >>> --- >>> lib/zstd/Makefile | 18 ++++++++---------- >>> lib/zstd/common/entropy_common.c | 4 +++- >>> lib/zstd/common/zstd_common.c | 7 +++++++ >>> lib/Kconfig | 8 ++++++-- >>> 4 files changed, 24 insertions(+), 13 deletions(-) >>> >>> diff --git a/lib/zstd/Makefile b/lib/zstd/Makefile >>> index fc45339fc3a3..440bd0007ae2 100644 >>> --- a/lib/zstd/Makefile >>> +++ b/lib/zstd/Makefile >>> @@ -10,14 +10,10 @@ >>> # ################################################################ >>> obj-$(CONFIG_ZSTD_COMPRESS) += zstd_compress.o >>> obj-$(CONFIG_ZSTD_DECOMPRESS) += zstd_decompress.o >>> +obj-$(CONFIG_ZSTD_COMMON) += zstd_common.o >>> zstd_compress-y := \ >>> zstd_compress_module.o \ >>> - common/debug.o \ >>> - common/entropy_common.o \ >>> - common/error_private.o \ >>> - common/fse_decompress.o \ >>> - common/zstd_common.o \ >>> compress/fse_compress.o \ >>> compress/hist.o \ >>> compress/huf_compress.o \ >>> @@ -33,12 +29,14 @@ zstd_compress-y := \ >>> zstd_decompress-y := \ >>> zstd_decompress_module.o \ >>> - common/debug.o \ >>> - common/entropy_common.o \ >>> - common/error_private.o \ >>> - common/fse_decompress.o \ >>> - common/zstd_common.o \ >>> decompress/huf_decompress.o \ >>> decompress/zstd_ddict.o \ >>> decompress/zstd_decompress.o \ >>> decompress/zstd_decompress_block.o \ >>> + >>> +zstd_common-y := \ >>> + common/debug.o \ >>> + common/entropy_common.o \ >>> + common/error_private.o \ >>> + common/fse_decompress.o \ >>> + common/zstd_common.o \ >>> diff --git a/lib/zstd/common/entropy_common.c >>> b/lib/zstd/common/entropy_common.c >>> index 53b47a2b52ff..f84612627471 100644 >>> --- a/lib/zstd/common/entropy_common.c >>> +++ b/lib/zstd/common/entropy_common.c >>> @@ -15,6 +15,7 @@ >>> /* ************************************* >>> * Dependencies >>> ***************************************/ >>> +#include <linux/module.h> >>> #include "mem.h" >>> #include "error_private.h" /* ERR_*, ERROR */ >>> #define FSE_STATIC_LINKING_ONLY /* FSE_MIN_TABLELOG */ >>> @@ -239,7 +240,7 @@ size_t FSE_readNCount( >>> { >>> return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, >>> tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0); >>> } >>> - >>> +EXPORT_SYMBOL_GPL(FSE_readNCount); >>> /*! HUF_readStats() : >>> Read compact Huffman tree, saved by HUF_writeCTable(). >>> @@ -255,6 +256,7 @@ size_t HUF_readStats(BYTE* huffWeight, size_t >>> hwSize, U32* rankStats, >>> U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32]; >>> return HUF_readStats_wksp(huffWeight, hwSize, rankStats, >>> nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* bmi2 >>> */ 0); >>> } >>> +EXPORT_SYMBOL_GPL(HUF_readStats); >>> FORCE_INLINE_TEMPLATE size_t >>> HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats, >>> diff --git a/lib/zstd/common/zstd_common.c >>> b/lib/zstd/common/zstd_common.c >>> index 3d7e35b309b5..06f62b2026d5 100644 >>> --- a/lib/zstd/common/zstd_common.c >>> +++ b/lib/zstd/common/zstd_common.c >>> @@ -13,6 +13,7 @@ >>> /*-************************************* >>> * Dependencies >>> ***************************************/ >>> +#include <linux/module.h> >>> #define ZSTD_DEPS_NEED_MALLOC >>> #include "zstd_deps.h" /* ZSTD_malloc, ZSTD_calloc, ZSTD_free, >>> ZSTD_memset */ >>> #include "error_private.h" >>> @@ -59,6 +60,7 @@ void* ZSTD_customMalloc(size_t size, ZSTD_customMem >>> customMem) >>> return customMem.customAlloc(customMem.opaque, size); >>> return ZSTD_malloc(size); >>> } >>> +EXPORT_SYMBOL_GPL(ZSTD_customMalloc); >>> void* ZSTD_customCalloc(size_t size, ZSTD_customMem customMem) >>> { >>> @@ -71,6 +73,7 @@ void* ZSTD_customCalloc(size_t size, ZSTD_customMem >>> customMem) >>> } >>> return ZSTD_calloc(1, size); >>> } >>> +EXPORT_SYMBOL_GPL(ZSTD_customCalloc); >>> void ZSTD_customFree(void* ptr, ZSTD_customMem customMem) >>> { >>> @@ -81,3 +84,7 @@ void ZSTD_customFree(void* ptr, ZSTD_customMem >>> customMem) >>> ZSTD_free(ptr); >>> } >>> } >>> +EXPORT_SYMBOL_GPL(ZSTD_customFree); >>> + >>> +MODULE_LICENSE("Dual BSD/GPL"); >>> +MODULE_DESCRIPTION("Zstd Common"); >>> diff --git a/lib/Kconfig b/lib/Kconfig >>> index 087e06b4cdfd..33f3a7054cdd 100644 >>> --- a/lib/Kconfig >>> +++ b/lib/Kconfig >>> @@ -333,12 +333,16 @@ config LZ4HC_COMPRESS >>> config LZ4_DECOMPRESS >>> tristate >>> +config ZSTD_COMMON >>> + select XXHASH >>> + tristate >>> + >>> config ZSTD_COMPRESS >>> - select XXHASH >>> + select ZSTD_COMMON >>> tristate >>> config ZSTD_DECOMPRESS >>> - select XXHASH >>> + select ZSTD_COMMON >>> tristate >>> source "lib/xz/Kconfig" >>> -- >>> 2.30.2 >>> >>> >
-- Alexey
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