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authorSteven Rostedt <srostedt@redhat.com>2012-04-24 22:32:06 -0400
committerSteven Rostedt <rostedt@goodmis.org>2012-05-16 19:58:44 -0400
commit9fd49328fc2a1cbfea542bcbcf004b5c81dc495b (patch)
treeda8f42d3483da2b1b224d422db074cbe954b5cd3
parent71babb2705e2203a64c27ede13ae3508a0d2c16c (diff)
ftrace: Sort all function addresses, not just per page
Instead of just sorting the ip's of the functions per ftrace page, sort the entire list before adding them to the ftrace pages. This will allow the bsearch algorithm to be sped up as it can also sort by pages, not just records within a page. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--include/asm-generic/vmlinux.lds.h2
-rw-r--r--kernel/trace/ftrace.c34
2 files changed, 23 insertions, 13 deletions
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 8aeadf6b553..4e2e1cc505a 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -486,8 +486,8 @@
CPU_DISCARD(init.data) \
MEM_DISCARD(init.data) \
KERNEL_CTORS() \
- *(.init.rodata) \
MCOUNT_REC() \
+ *(.init.rodata) \
FTRACE_EVENTS() \
TRACE_SYSCALLS() \
DEV_DISCARD(init.rodata) \
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index cf81f27ce6c..53ed01ed7aa 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3666,15 +3666,27 @@ static __init int ftrace_init_dyn_debugfs(struct dentry *d_tracer)
return 0;
}
-static void ftrace_swap_recs(void *a, void *b, int size)
+static int ftrace_cmp_ips(const void *a, const void *b)
{
- struct dyn_ftrace *reca = a;
- struct dyn_ftrace *recb = b;
- struct dyn_ftrace t;
+ const unsigned long *ipa = a;
+ const unsigned long *ipb = b;
- t = *reca;
- *reca = *recb;
- *recb = t;
+ if (*ipa > *ipb)
+ return 1;
+ if (*ipa < *ipb)
+ return -1;
+ return 0;
+}
+
+static void ftrace_swap_ips(void *a, void *b, int size)
+{
+ unsigned long *ipa = a;
+ unsigned long *ipb = b;
+ unsigned long t;
+
+ t = *ipa;
+ *ipa = *ipb;
+ *ipb = t;
}
static int ftrace_process_locs(struct module *mod,
@@ -3693,6 +3705,9 @@ static int ftrace_process_locs(struct module *mod,
if (!count)
return 0;
+ sort(start, count, sizeof(*start),
+ ftrace_cmp_ips, ftrace_swap_ips);
+
pg = ftrace_allocate_pages(count);
if (!pg)
return -ENOMEM;
@@ -3740,11 +3755,6 @@ static int ftrace_process_locs(struct module *mod,
/* These new locations need to be initialized */
ftrace_new_pgs = pg;
- /* Make each individual set of pages sorted by ips */
- for (; pg; pg = pg->next)
- sort(pg->records, pg->index, sizeof(struct dyn_ftrace),
- ftrace_cmp_recs, ftrace_swap_recs);
-
/*
* We only need to disable interrupts on start up
* because we are modifying code that an interrupt