The patch titled
Subject: x86_64: select DYNAMIC_DEBUG_RELATIVE_POINTERS
has been added to the -mm tree. Its filename is
x86-64-select-dynamic_debug_relative_pointers.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/x86-64-select-dynamic_debug_relative_pointers.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/x86-64-select-dynamic_debug_relative_pointers.patch
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------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: x86_64: select DYNAMIC_DEBUG_RELATIVE_POINTERS
This reduces the size of struct _ddebug from 56 to 40 bytes. There's one
such struct for each pr_debug(), netdev_debug() etc. in a
CONFIG_DYNAMIC_DEBUG kernel. An Ubuntu 4.15 kernel has about 2550 entries
in the __verbose section of vmlinux, amounting to ~40K saved. (Modules
also become smaller, but it's harder to quantify how much that yields at
runtime.)
For comparison, the __bug_table section of that Ubuntu kernel is 75576
bytes, i.e. 6298 12-byte bug_entrys, so GENERIC_BUG_RELATIVE_POINTERS
saves ~50K.
Due to the build-time sanity checks in asm-generic/dynamic_debug.h, we
need to add another #undef to vclock_gettime.c.
Link: http://lkml.kernel.org/r/20190409212517.7321-9-linux@xxxxxxxxxxxxxxxxxx
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jason Baron <jbaron@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Petr Mladek <pmladek@xxxxxxxx>
Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/Kconfig | 1 +
arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 +
arch/x86/include/asm/Kbuild | 1 +
3 files changed, 3 insertions(+)
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c~x86-64-select-dynamic_debug_relative_pointers
+++ a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -17,6 +17,7 @@
#undef CONFIG_ILLEGAL_POINTER_VALUE
#undef CONFIG_SPARSEMEM_VMEMMAP
#undef CONFIG_NR_CPUS
+#undef CONFIG_DYNAMIC_DEBUG_RELATIVE_POINTERS
#define CONFIG_X86_32 1
#define CONFIG_PGTABLE_LEVELS 2
--- a/arch/x86/include/asm/Kbuild~x86-64-select-dynamic_debug_relative_pointers
+++ a/arch/x86/include/asm/Kbuild
@@ -7,6 +7,7 @@ generated-y += unistd_64_x32.h
generated-y += xen-hypercalls.h
generic-y += dma-contiguous.h
+generic-y += dynamic_debug.h
generic-y += early_ioremap.h
generic-y += export.h
generic-y += mcs_spinlock.h
--- a/arch/x86/Kconfig~x86-64-select-dynamic_debug_relative_pointers
+++ a/arch/x86/Kconfig
@@ -30,6 +30,7 @@ config X86_64
select SWIOTLB
select X86_DEV_DMA_OPS
select ARCH_HAS_SYSCALL_WRAPPER
+ select DYNAMIC_DEBUG_RELATIVE_POINTERS
#
# Arch settings
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
linux-deviceh-use-unique-identifier-for-each-struct-_ddebug.patch
linux-neth-use-unique-identifier-for-each-struct-_ddebug.patch
linux-printkh-use-unique-identifier-for-each-struct-_ddebug.patch
dynamic_debug-introduce-accessors-for-string-members-of-struct-_ddebug.patch
dynamic_debug-drop-use-of-bitfields-in-struct-_ddebug.patch
dynamic_debug-introduce-config_dynamic_debug_relative_pointers.patch
dynamic_debug-add-asm-generic-implementation-for-dynamic_debug_relative_pointers.patch
x86-64-select-dynamic_debug_relative_pointers.patch
arm64-select-dynamic_debug_relative_pointers.patch
powerpc-select-dynamic_debug_relative_pointers-for-ppc64.patch
lib-bitmapc-remove-unused-export_symbols.patch
lib-bitmapc-guard-exotic-bitmap-functions-by-config_numa.patch
bitopsh-sanitize-rotate-primitives.patch
