Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751817AbbBMFs4 (ORCPT ); Fri, 13 Feb 2015 00:48:56 -0500 Received: from szxga03-in.huawei.com ([119.145.14.66]:23022 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751236AbbBMFsy (ORCPT ); Fri, 13 Feb 2015 00:48:54 -0500 From: Wang Nan To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , CC: , , , Subject: [RFC PATCH v3 06/26] ftrace: sort ftrace entries earlier. Date: Fri, 13 Feb 2015 13:40:31 +0800 Message-ID: <1423806031-61742-1-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.4 In-Reply-To: <1423805941-61407-1-git-send-email-wangnan0@huawei.com> References: <1423805941-61407-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.54DD8FEA.0051,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: d0b8534d32769079747c100e55810b7d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3476 Lines: 120 By extracting mcount sorting code and sort them earliler, futher patches will be able to determine whether an address is on an ftrace entry or not using bsearch(). ftrace_sort_mcount_area() will be called before, during and after ftrace_init (when module insertion). Ensure it sort kernel mcount table only once. Signed-off-by: Wang Nan --- include/linux/ftrace.h | 2 ++ init/main.c | 1 + kernel/trace/ftrace.c | 38 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 39 insertions(+), 2 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 1da6029..8db315a 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -701,8 +701,10 @@ static inline void __ftrace_enabled_restore(int enabled) #ifdef CONFIG_FTRACE_MCOUNT_RECORD extern void ftrace_init(void); +extern void ftrace_init_early(void); #else static inline void ftrace_init(void) { } +static inline void ftrace_init_early(void) { } #endif /* diff --git a/init/main.c b/init/main.c index 6f0f1c5f..eaafc3e 100644 --- a/init/main.c +++ b/init/main.c @@ -517,6 +517,7 @@ asmlinkage __visible void __init start_kernel(void) boot_cpu_init(); page_address_init(); pr_notice("%s", linux_banner); + ftrace_init_early(); setup_arch(&command_line); mm_init_cpumask(&init_mm); setup_command_line(command_line); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 6c6cbb1..a75cfbe 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1169,6 +1169,7 @@ struct ftrace_page { static struct ftrace_page *ftrace_pages_start; static struct ftrace_page *ftrace_pages; +static bool kernel_mcount_sorted = false; static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash) { @@ -4743,6 +4744,32 @@ static void ftrace_swap_ips(void *a, void *b, int size) *ipb = t; } +static void ftrace_sort_mcount_area(unsigned long *start, unsigned long *end) +{ + extern unsigned long __start_mcount_loc[]; + extern unsigned long __stop_mcount_loc[]; + + unsigned long count; + bool is_kernel_mcount; + + count = end - start; + if (!count) + return; + + is_kernel_mcount = + (start == __start_mcount_loc) && + (end == __stop_mcount_loc); + + if (is_kernel_mcount && kernel_mcount_sorted) + return; + + sort(start, count, sizeof(*start), + ftrace_cmp_ips, ftrace_swap_ips); + + if (is_kernel_mcount) + kernel_mcount_sorted = true; +} + static int ftrace_process_locs(struct module *mod, unsigned long *start, unsigned long *end) @@ -4761,8 +4788,7 @@ static int ftrace_process_locs(struct module *mod, if (!count) return 0; - sort(start, count, sizeof(*start), - ftrace_cmp_ips, ftrace_swap_ips); + ftrace_sort_mcount_area(start, end); start_pg = ftrace_allocate_pages(count); if (!start_pg) @@ -4965,6 +4991,14 @@ void __init ftrace_init(void) ftrace_disabled = 1; } +void __init ftrace_init_early(void) +{ + extern unsigned long __start_mcount_loc[]; + extern unsigned long __stop_mcount_loc[]; + + ftrace_sort_mcount_area(__start_mcount_loc, __stop_mcount_loc); +} + /* Do nothing if arch does not support this */ void __weak arch_ftrace_update_trampoline(struct ftrace_ops *ops) { -- 1.8.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/