Re: [RFC PATCH v6] Documentation/arch: Add Documentation/arch-features.txt
flat view
From: Andrew Morton <hidden>
Date: 2015-05-13 22:05:30
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linux-arch, lkml
On Wed, 13 May 2015 09:27:57 -0700 Josh Triplett [off-list ref] wrote:
If we can't generate this, then the ASCII-art style and right-aligned feature names seems *really* likely to produce spurious conflicts, especially when adding a feature to the list. Even though it would produce a much longer file, would you consider dropping the tables and just having a section per feature?
me2. The patch conflicts are going to be pretty bad. I'd also prefer a format which allows us to add useful notes - it's a bit hostile to say "thou shalt implement X" without providing any info about how to do so. Where do we tell maintainers that there's a handy test app in tools/testing/selftests which they should use? This way, I can bug patch submitters with "hey, you forgot to update Documentation/arch-features.txt" and they will add useful info while it's all still hot in their minds. And there's a ton of stuff which can go in here, much of it not immediately apparent. Just grepping 9 months worth of the stuff I've handled, I'm seeing things like HAVE_ARCH_KASAN __HAVE_ARCH_PMDP_SPLITTING_FLUSH __HAVE_ARCH_PTE_SPECIAL __HAVE_ARCH_GATE_AREA ARCH_HAVE_ELF_ASLR ARCH_HAS_GCOV_PROFILE_ALL CONFIG_ARCH_USE_BUILTIN_BSWAP HAVE_ARCH_HUGE_VMAP ARCH_HAS_SG_CHAIN __HAVE_ARCH_STRNCASECMP ARCH_HAS_ELF_RANDOMIZE CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT CONFIG_ARCH_USES_PG_UNCACHED CONFIG_ARCH_HAS_WALK_MEMORY and things which don't contain ARCH HAVE_GENERIC_RCU_GUP HAVE_RCU_TABLE_FREE HAVE_GENERIC_RCU_GUP CONFIG_HAVE_CLK CONFIG_HAVE_IOREMAP_PROT CONFIG_HAVE_MEMBLOCK_NODE_MAP And then there's the increasingly common arch/include/asm/foo.h: static inline void wibble(...) { ... } #define wibble wibble include/linux/foo.h: #ifndef wibble static inline void wibble(...) { ... } #define wibble #endif which is going to be hard to grep for.... ugh, this thing's going to be enormous. People will go insane reading it, so each section should have a sentence describing what the feature does so maintainers can make quick decisions about whether they should bother.