From e94142a67f8bad494c593f0a07c9fc2fbec98c0e Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Fri, 13 Mar 2009 17:51:27 +0800 Subject: [PATCH] ftrace: remove struct list_head from struct dyn_ftrace Impact: save memory The struct dyn_ftrace table is very large, this patch will save about 50%. Signed-off-by: Lai Jiangshan Cc: Steven Rostedt LKML-Reference: <49BA2C9F.8020009@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- include/linux/ftrace.h | 1 - kernel/trace/ftrace.c | 14 ++++++++------ 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index c146c1021a2..9d598bbf28a 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -145,7 +145,6 @@ enum { }; struct dyn_ftrace { - struct list_head list; unsigned long ip; /* address of mcount call-site */ unsigned long flags; struct dyn_arch_ftrace arch; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index bf78a4c75c6..90d5729afef 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -272,7 +272,7 @@ enum { static int ftrace_filtered; -static LIST_HEAD(ftrace_new_addrs); +static struct dyn_ftrace *ftrace_new_addrs; static DEFINE_MUTEX(ftrace_regex_lock); @@ -409,8 +409,8 @@ ftrace_record_ip(unsigned long ip) return NULL; rec->ip = ip; - - list_add(&rec->list, &ftrace_new_addrs); + rec->flags = (unsigned long)ftrace_new_addrs; + ftrace_new_addrs = rec; return rec; } @@ -716,19 +716,21 @@ unsigned long ftrace_update_tot_cnt; static int ftrace_update_code(struct module *mod) { - struct dyn_ftrace *p, *t; + struct dyn_ftrace *p; cycle_t start, stop; start = ftrace_now(raw_smp_processor_id()); ftrace_update_cnt = 0; - list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) { + while (ftrace_new_addrs) { /* If something went wrong, bail without enabling anything */ if (unlikely(ftrace_disabled)) return -1; - list_del_init(&p->list); + p = ftrace_new_addrs; + ftrace_new_addrs = (struct dyn_ftrace *)p->flags; + p->flags = 0L; /* convert record (i.e, patch mcount-call with NOP) */ if (ftrace_code_disable(mod, p)) { -- 2.41.1