From patchwork Thu Sep 8 13:09:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Leizhen (ThunderTown)" X-Patchwork-Id: 12970056 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDB5FC54EE9 for ; Thu, 8 Sep 2022 13:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229546AbiIHNKq (ORCPT ); Thu, 8 Sep 2022 09:10:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232057AbiIHNKc (ORCPT ); Thu, 8 Sep 2022 09:10:32 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B82E55F20F; Thu, 8 Sep 2022 06:10:11 -0700 (PDT) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MNfX90jnXzjXLP; Thu, 8 Sep 2022 21:06:33 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 8 Sep 2022 21:10:09 +0800 Received: from thunder-town.china.huawei.com (10.174.178.55) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 8 Sep 2022 21:10:08 +0800 From: Zhen Lei To: Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , , , Masahiro Yamada , Alexei Starovoitov , Jiri Olsa , Kees Cook , Andrew Morton , "Luis Chamberlain" , CC: Zhen Lei Subject: [PATCH 0/7] kallsyms: Optimizes the performance of lookup symbols Date: Thu, 8 Sep 2022 21:09:29 +0800 Message-ID: <20220908130936.674-1-thunder.leizhen@huawei.com> X-Mailer: git-send-email 2.26.0.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.178.55] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Currently, to search for a symbol, we need to expand the symbols in 'kallsyms_names' one by one, and then use the expanded string for comparison. This is very slow. In fact, we can first compress the name being looked up and then use it for comparison when traversing 'kallsyms_names'. This patch series optimizes the performance of function kallsyms_lookup_name(), and function klp_find_object_symbol() in the livepatch module. Based on the test results, the performance overhead is reduced to 5%. That is, the performance of these functions is improved by 20 times. To avoid increasing the kernel size in non-debug mode, the optimization is only for the case CONFIG_KALLSYMS_ALL=y. Zhen Lei (7): scripts/kallsyms: don't compress symbol type when CONFIG_KALLSYMS_ALL=y scripts/kallsyms: rename build_initial_tok_table() kallsyms: Adjust the types of some local variables kallsyms: Improve the performance of kallsyms_lookup_name() kallsyms: Add helper kallsyms_on_each_match_symbol() livepatch: Use kallsyms_on_each_match_symbol() to improve performance livepatch: Improve the search performance of module_kallsyms_on_each_symbol() include/linux/kallsyms.h | 8 +++ kernel/kallsyms.c | 135 +++++++++++++++++++++++++++++++++++++-- kernel/livepatch/core.c | 25 ++++++-- kernel/module/kallsyms.c | 13 +++- scripts/kallsyms.c | 19 ++++-- 5 files changed, 184 insertions(+), 16 deletions(-)