From: "Leizhen (ThunderTown)" <thunder.leizhen@huawei.com>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>,
Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
Petr Mladek <pmladek@suse.com>,
Joe Lawrence <joe.lawrence@redhat.com>,
<live-patching@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
Masahiro Yamada <masahiroy@kernel.org>,
Alexei Starovoitov <ast@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
<linux-modules@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
"Ingo Molnar" <mingo@redhat.com>
Subject: Re: [PATCH v7 00/11] kallsyms: Optimizes the performance of lookup symbols
Date: Wed, 2 Nov 2022 17:18:25 +0800 [thread overview]
Message-ID: <d059c054-1ef9-f89b-fcb2-7387770d2ec7@huawei.com> (raw)
In-Reply-To: <b30a540b-019d-4466-19d9-33900b1a89b1@huawei.com>
On 2022/10/31 23:04, Leizhen (ThunderTown) wrote:
> Now, we need to make a decision. Choose one of the two:
> 1. Continue with my current approach. Improve the average performance of
> kallsyms_lookup_name() by 20 to 30 times. The memory overhead is increased by:
> arm64 (defconfig):
> 73.5KiB and 4.0% if CONFIG_KALLSYMS_ALL=y.
> 19.8KiB and 2.8% if CONFIG_KALLSYMS_ALL=n.
> x86 (defconfig):
> 49.0KiB and 3.0% if CONFIG_KALLSYMS_ALL=y.
> 16.8KiB and 2.3% if CONFIG_KALLSYMS_ALL=n.
> 2. Sort names, binary search (The static function causes duplicate names. Additional work is required）
> 2^18=262144, only up to 18 symbol expansions and comparisons are required.
> The performance is definitely excellent, although I haven't tested it yet.
> The memory overhead is increased by: 6 * kallsyms_num_syms
> arm64 (defconfig):
> 1MiB if CONFIG_KALLSYMS_ALL=y.
> 362KiB if CONFIG_KALLSYMS_ALL=n.
> x86 (defconfig):
> 770KiB if CONFIG_KALLSYMS_ALL=y.
> 356KiB if CONFIG_KALLSYMS_ALL=n.
Hi, Luis:
I've implemented v8 based on method 2(Sort names, binary search).
The memory overhead is increased by: 3 * kallsyms_num_syms.
kallsyms_offsets_of_names[] is not added in v8 because it does not help
much in performance improvement, so save (3 * kallsyms_num_syms) bytes.
For details about the performance data, please see the commit message.
--
Regards,
Zhen Lei
prev parent reply other threads:[~2022-11-02 9:20 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 6:49 [PATCH v7 00/11] kallsyms: Optimizes the performance of lookup symbols Zhen Lei
2022-10-17 6:49 ` [PATCH v7 01/11] scripts/kallsyms: rename build_initial_tok_table() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 02/11] scripts/kallsyms: don't compress symbol types Zhen Lei
2022-10-17 6:49 ` [PATCH v7 03/11] scripts/kallsyms: remove helper sym_name() and cleanup Zhen Lei
2022-10-17 6:49 ` [PATCH v7 04/11] kallsyms: Add helper kallsyms_compress_symbol_name() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 05/11] kallsyms: Improve the performance of kallsyms_lookup_name() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 06/11] kallsyms: Improve the performance of kallsyms_lookup_name() when CONFIG_LTO_CLANG=y Zhen Lei
2022-10-17 6:49 ` [PATCH v7 07/11] kallsyms: Add helper kallsyms_on_each_match_symbol() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 08/11] livepatch: Use kallsyms_on_each_match_symbol() to improve performance Zhen Lei
2022-10-17 6:49 ` [PATCH v7 09/11] livepatch: Improve the search performance of module_kallsyms_on_each_symbol() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 10/11] kallsyms: Delete an unused parameter related to kallsyms_on_each_symbol() Zhen Lei
2022-10-17 6:49 ` [PATCH v7 11/11] kallsyms: Add self-test facility Zhen Lei
2022-10-18 8:21 ` kernel test robot
2022-10-18 9:11 ` Leizhen (ThunderTown)
2022-10-18 9:11 ` Leizhen
2022-10-18 9:32 ` kernel test robot
2022-10-19 8:39 ` Leizhen (ThunderTown)
2022-10-19 8:39 ` Leizhen
2022-10-21 2:00 ` kernel test robot
2022-10-19 12:01 ` [PATCH v7 00/11] kallsyms: Optimizes the performance of lookup symbols Luis Chamberlain
2022-10-19 14:11 ` Leizhen (ThunderTown)
2022-10-25 17:53 ` Luis Chamberlain
2022-10-26 6:44 ` Leizhen (ThunderTown)
2022-10-26 19:03 ` Luis Chamberlain
2022-10-27 3:26 ` Leizhen (ThunderTown)
2022-10-27 6:27 ` Leizhen (ThunderTown)
2022-10-29 8:10 ` Leizhen (ThunderTown)
2022-10-29 12:49 ` David Laight
2022-10-31 2:55 ` Leizhen (ThunderTown)
2022-10-31 4:55 ` Leizhen (ThunderTown)
2022-10-31 15:04 ` Leizhen (ThunderTown)
2022-11-02 9:18 ` Leizhen (ThunderTown) [this message]
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