From: "tip-bot2 for Peter Zijlstra" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
Miroslav Benes <mbenes@suse.cz>,
Josh Poimboeuf <jpoimboe@redhat.com>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: core/objtool] objtool: Optimize find_section_by_name()
Date: Thu, 26 Mar 2020 10:08:35 -0000 [thread overview]
Message-ID: <158521731555.28353.11326523921308261337.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200324160924.440174280@infradead.org>
The following commit has been merged into the core/objtool branch of tip:
Commit-ID: ae358196fac3a0b4d2a7d47a4f401e3421027b03
Gitweb: https://git.kernel.org/tip/ae358196fac3a0b4d2a7d47a4f401e3421027b03
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 12 Mar 2020 09:32:10 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 25 Mar 2020 18:28:29 +01:00
objtool: Optimize find_section_by_name()
In order to avoid yet another linear search of (20k) sections, add a
name based hash.
This reduces objtool runtime on vmlinux.o by some 10s to around 35s.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200324160924.440174280@infradead.org
---
tools/objtool/elf.c | 10 +++++++++-
tools/objtool/elf.h | 3 +++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 9007713..20fe40d 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -22,11 +22,16 @@
#define MAX_NAME_LEN 128
+static inline u32 str_hash(const char *str)
+{
+ return jhash(str, strlen(str), 0);
+}
+
struct section *find_section_by_name(struct elf *elf, const char *name)
{
struct section *sec;
- list_for_each_entry(sec, &elf->sections, list)
+ hash_for_each_possible(elf->section_name_hash, sec, name_hash, str_hash(name))
if (!strcmp(sec->name, name))
return sec;
@@ -202,6 +207,7 @@ static int read_sections(struct elf *elf)
list_add_tail(&sec->list, &elf->sections);
hash_add(elf->section_hash, &sec->hash, sec->idx);
+ hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
}
if (stats)
@@ -441,6 +447,7 @@ struct elf *elf_read(const char *name, int flags)
hash_init(elf->symbol_hash);
hash_init(elf->section_hash);
+ hash_init(elf->section_name_hash);
INIT_LIST_HEAD(&elf->sections);
elf->fd = open(name, flags);
@@ -581,6 +588,7 @@ struct section *elf_create_section(struct elf *elf, const char *name,
list_add_tail(&sec->list, &elf->sections);
hash_add(elf->section_hash, &sec->hash, sec->idx);
+ hash_add(elf->section_name_hash, &sec->name_hash, str_hash(sec->name));
return sec;
}
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index 8c272eb..ac7c46f 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -10,6 +10,7 @@
#include <gelf.h>
#include <linux/list.h>
#include <linux/hashtable.h>
+#include <linux/jhash.h>
#ifdef LIBELF_USE_DEPRECATED
# define elf_getshdrnum elf_getshnum
@@ -26,6 +27,7 @@
struct section {
struct list_head list;
struct hlist_node hash;
+ struct hlist_node name_hash;
GElf_Shdr sh;
struct list_head symbol_list;
struct list_head rela_list;
@@ -73,6 +75,7 @@ struct elf {
struct list_head sections;
DECLARE_HASHTABLE(symbol_hash, 20);
DECLARE_HASHTABLE(section_hash, 16);
+ DECLARE_HASHTABLE(section_name_hash, 16);
};
next prev parent reply other threads:[~2020-03-26 10:09 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-24 15:31 [PATCH v3 00/26] objtool: vmlinux.o and noinstr validation Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 01/26] objtool: Introduce validate_return() Peter Zijlstra
2020-03-25 8:39 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 02/26] objtool: Rename func_for_each_insn() Peter Zijlstra
2020-03-25 8:43 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 03/26] objtool: Rename func_for_each_insn_all() Peter Zijlstra
2020-03-25 8:44 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 04/26] x86/kexec: Use RIP relative addressing Peter Zijlstra
2020-03-25 9:34 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 05/26] x86/kexec: Make relocate_kernel_64.S objtool clean Peter Zijlstra
2020-03-24 20:55 ` Josh Poimboeuf
2020-03-25 9:56 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 06/26] objtool: Optimize find_symbol_by_index() Peter Zijlstra
2020-03-25 10:01 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 07/26] objtool: Add a statistics mode Peter Zijlstra
2020-03-25 10:10 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 08/26] objtool: Optimize find_section_by_index() Peter Zijlstra
2020-03-25 10:12 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 09/26] objtool: Optimize find_section_by_name() Peter Zijlstra
2020-03-25 10:18 ` Miroslav Benes
2020-03-26 10:08 ` tip-bot2 for Peter Zijlstra [this message]
2020-03-24 15:31 ` [PATCH v3 10/26] objtool: Optimize find_symbol_*() and read_symbols() Peter Zijlstra
2020-03-25 10:20 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 11/26] objtool: Rename find_containing_func() Peter Zijlstra
2020-03-25 10:21 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 12/26] objtool: Resize insn_hash Peter Zijlstra
2020-03-25 10:21 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 13/26] objtool: Optimize find_symbol_by_name() Peter Zijlstra
2020-03-25 10:25 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 14/26] objtool: Optimize read_sections() Peter Zijlstra
2020-03-25 12:10 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-04-21 14:47 ` [PATCH v3 14/26] " youling257
2020-04-21 15:49 ` Peter Zijlstra
2020-04-21 15:57 ` Borislav Petkov
2020-04-21 17:50 ` youling 257
2020-03-24 15:31 ` [PATCH v3 15/26] objtool: Delete cleanup() Peter Zijlstra
2020-03-25 12:11 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 16/26] objtool: Optimize find_rela_by_dest_range() Peter Zijlstra
2020-03-25 12:19 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 17/26] objtool: Re-arrange validate_functions() Peter Zijlstra
2020-03-24 21:10 ` Josh Poimboeuf
2020-03-24 21:15 ` Peter Zijlstra
2020-03-25 12:22 ` Miroslav Benes
2020-03-26 10:08 ` [tip: core/objtool] " tip-bot2 for Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 18/26] objtool: Fix !CFI insn_state propagation Peter Zijlstra
2020-03-24 21:40 ` Josh Poimboeuf
2020-03-24 22:11 ` Peter Zijlstra
2020-03-24 23:00 ` Peter Zijlstra
2020-03-25 14:39 ` Josh Poimboeuf
2020-03-25 14:41 ` [PATCH v3.1 18a/26] objtool: Remove CFI save/restore special case Peter Zijlstra
2020-03-25 14:42 ` [PATCH v3.1 18b/26] objtool: Factor out CFI hints Peter Zijlstra
2020-03-25 14:43 ` [PATCH v3.1 18c/26] objtool: Rename struct cfi_state Peter Zijlstra
2020-03-25 14:43 ` [PATCH v3.1 18d/26] objtool: Fix !CFI insn_state propagation Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 19/26] objtool: Implement noinstr validation Peter Zijlstra
2020-03-24 21:41 ` Josh Poimboeuf
2020-03-25 14:44 ` [PATCH v3.1 " Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 20/26] objtool: Optimize !vmlinux.o again Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 21/26] objtool: Use sec_offset_hash() for insn_hash Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 22/26] objtool: Detect loading function pointers across noinstr Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 23/26] kbuild/objtool: Add objtool-vmlinux.o pass Peter Zijlstra
2020-03-24 22:03 ` Josh Poimboeuf
2020-03-24 22:05 ` Peter Zijlstra
2020-03-24 15:31 ` [PATCH v3 24/26] objtool: Avoid iterating !text section symbols Peter Zijlstra
2020-03-24 22:09 ` Josh Poimboeuf
2020-03-24 15:31 ` [PATCH v3 25/26] objtool: Rearrange validate_section() Peter Zijlstra
2020-03-24 22:10 ` Josh Poimboeuf
2020-03-24 15:31 ` [PATCH v3 26/26] objtool: Add STT_NOTYPE noinstr validation Peter Zijlstra
2020-03-24 22:16 ` Josh Poimboeuf
2020-03-24 22:34 ` Peter Zijlstra
2020-03-25 14:42 ` Josh Poimboeuf
2020-03-25 15:53 ` Peter Zijlstra
2020-03-25 16:40 ` Josh Poimboeuf
2020-03-25 16:50 ` Peter Zijlstra
2020-03-26 8:01 ` Julien Thierry
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