From patchwork Thu Jun 13 13:37:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zheng Yejian X-Patchwork-Id: 13696819 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D432143895; Thu, 13 Jun 2024 13:36:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718285806; cv=none; b=CwlFCubDjKZCWD/SYz1Llles54Zz9OVIVrietdqAfQJNVRA/2+Kq8fCnfPn82KTkWbSVlfRulnkkIG6VEdGqQS9ZscPyeXjuUDEWAGuV4mToLKHQUdtrLxe1I1k9/76viOmP7KCgXMWZGi5lpJBfopBoYN7WlbkXGyjoe7LMrX8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718285806; c=relaxed/simple; bh=yvYdIaOxLkBHXijF6E3fTBqJ6CWJ8PSOywo3i6oeeQY=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QWzSp0dCurcYhcnkldugZZqcFrK4H7Rr68GGVNe2JwE9b1gvWbeWnjRL69Q4upJQ8E3sJvBEwZCo6m+7ii8Jyt6pRFsuiX/qVOpayig9u8b4Phcjg+yYzQApzR4K+Ej+ZvFCJ9CRatsrffFkApTh02ox440j4Aw3SNFpXjRE5yE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4W0Ncy4kpHzxSCx; Thu, 13 Jun 2024 21:32:34 +0800 (CST) Received: from dggpeml500012.china.huawei.com (unknown [7.185.36.15]) by mail.maildlp.com (Postfix) with ESMTPS id 5229B140258; Thu, 13 Jun 2024 21:36:40 +0800 (CST) Received: from localhost.localdomain (10.67.175.61) by dggpeml500012.china.huawei.com (7.185.36.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Thu, 13 Jun 2024 21:36:39 +0800 From: Zheng Yejian To: , , , , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Subject: [PATCH 1/6] kallsyms: Optimize multiple times of realloc() to one time of malloc() Date: Thu, 13 Jun 2024 21:37:06 +0800 Message-ID: <20240613133711.2867745-2-zhengyejian1@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240613133711.2867745-1-zhengyejian1@huawei.com> References: <20240613133711.2867745-1-zhengyejian1@huawei.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggpeml500012.china.huawei.com (7.185.36.15) Array 'table' is used to store pointers of symbols that read from in.map file, and its size depends on the number of symbols. Currently 'table' is expanded by calling realloc() every 10000 symbols read. However, there generally are around 100000+ symbols, which means that the expansion is generally 10+ times. As an optimization, introduce linked list 'sym_list' to associate and count all symbols, then store them into 'table' at one time. Signed-off-by: Zheng Yejian --- scripts/kallsyms.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/scripts/kallsyms.c b/scripts/kallsyms.c index 47978efe4797..6559a9802f6e 100644 --- a/scripts/kallsyms.c +++ b/scripts/kallsyms.c @@ -33,6 +33,7 @@ #define KSYM_NAME_LEN 512 struct sym_entry { + struct sym_entry *next; unsigned long long addr; unsigned int len; unsigned int seq; @@ -60,7 +61,8 @@ static struct addr_range percpu_range = { }; static struct sym_entry **table; -static unsigned int table_size, table_cnt; +static struct sym_entry *sym_list; +static unsigned int table_cnt; static int all_symbols; static int absolute_percpu; static int base_relative; @@ -273,6 +275,7 @@ static void read_map(const char *in) struct sym_entry *sym; char *buf = NULL; size_t buflen = 0; + int i; fp = fopen(in, "r"); if (!fp) { @@ -286,18 +289,22 @@ static void read_map(const char *in) continue; sym->start_pos = table_cnt; - - if (table_cnt >= table_size) { - table_size += 10000; - table = realloc(table, sizeof(*table) * table_size); - if (!table) { - fprintf(stderr, "out of memory\n"); - fclose(fp); - exit (1); - } - } - - table[table_cnt++] = sym; + table_cnt++; + sym->next = sym_list; + sym_list = sym; + } + table = malloc(sizeof(*table) * table_cnt); + if (!table) { + fprintf(stderr, "unable to allocate memory for table\n"); + free(buf); + fclose(fp); + exit(EXIT_FAILURE); + } + sym = sym_list; + i = table_cnt - 1; + while (sym) { + table[i--] = sym; + sym = sym->next; } free(buf);