From 8b946cc38e063f0f7bb67789478c38f6d7d457c9 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 24 Jun 2021 11:41:01 +0200 Subject: objtool: Introduce CFI hash Andi reported that objtool on vmlinux.o consumes more memory than his system has, leading to horrific performance. This is in part because we keep a struct instruction for every instruction in the file in-memory. Shrink struct instruction by removing the CFI state (which includes full register state) from it and demand allocating it. Given most instructions don't actually change CFI state, there's lots of repetition there, so add a hash table to find previous CFI instances. Reduces memory consumption (and runtime) for processing an x86_64-allyesconfig: pre: 4:40.84 real, 143.99 user, 44.18 sys, 30624988 mem post: 2:14.61 real, 108.58 user, 25.04 sys, 16396184 mem Suggested-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210624095147.756759107@infradead.org --- tools/objtool/include/objtool/arch.h | 2 +- tools/objtool/include/objtool/cfi.h | 2 ++ tools/objtool/include/objtool/check.h | 2 +- 3 files changed, 4 insertions(+), 2 deletions(-) (limited to 'tools/objtool/include') diff --git a/tools/objtool/include/objtool/arch.h b/tools/objtool/include/objtool/arch.h index 062bb6e9b865..a5ab6829511f 100644 --- a/tools/objtool/include/objtool/arch.h +++ b/tools/objtool/include/objtool/arch.h @@ -83,7 +83,7 @@ unsigned long arch_dest_reloc_offset(int addend); const char *arch_nop_insn(int len); -int arch_decode_hint_reg(struct instruction *insn, u8 sp_reg); +int arch_decode_hint_reg(u8 sp_reg, int *base); bool arch_is_retpoline(struct symbol *sym); diff --git a/tools/objtool/include/objtool/cfi.h b/tools/objtool/include/objtool/cfi.h index fd5cb0bed9bf..f11d1ac1dadf 100644 --- a/tools/objtool/include/objtool/cfi.h +++ b/tools/objtool/include/objtool/cfi.h @@ -7,6 +7,7 @@ #define _OBJTOOL_CFI_H #include +#include #define CFI_UNDEFINED -1 #define CFI_CFA -2 @@ -24,6 +25,7 @@ struct cfi_init_state { }; struct cfi_state { + struct hlist_node hash; /* must be first, cficmp() */ struct cfi_reg regs[CFI_NUM_REGS]; struct cfi_reg vals[CFI_NUM_REGS]; struct cfi_reg cfa; diff --git a/tools/objtool/include/objtool/check.h b/tools/objtool/include/objtool/check.h index 56d50bc50c10..07e99c25c7ac 100644 --- a/tools/objtool/include/objtool/check.h +++ b/tools/objtool/include/objtool/check.h @@ -60,7 +60,7 @@ struct instruction { struct list_head alts; struct symbol *func; struct list_head stack_ops; - struct cfi_state cfi; + struct cfi_state *cfi; }; static inline bool is_static_jump(struct instruction *insn) -- cgit v1.2.3