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ftrace: Replace record newlist with record page list

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As new functions come in to be initalized from mcount to nop,
they are done by groups of pages. Whether it is the core kernel
or a module. There's no need to keep track of these on a per record
basis.

At startup, and as any module is loaded, the functions to be
traced are stored in a group of pages and added to the function
list at the end. We just need to keep a pointer to the first
page of the list that was added, and use that to know where to
start on the list for initializing functions.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2011-12-16 16:30:31 -05:00 committed by Steven Rostedt
parent a790087554
commit 85ae32ae01
2 changed files with 38 additions and 35 deletions
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5
include/linux/ftrace.h
View File

@ -173,10 +173,7 @@ struct dyn_ftrace {
unsigned long ip; /* address of mcount call-site */
struct dyn_ftrace *freelist;
};
union {
unsigned long flags;
struct dyn_ftrace *newlist;
};
unsigned long flags;
struct dyn_arch_ftrace arch;
};

68
kernel/trace/ftrace.c
View File

@ -977,8 +977,6 @@ static struct ftrace_ops global_ops = {
.filter_hash = EMPTY_HASH,
};
static struct dyn_ftrace *ftrace_new_addrs;
static DEFINE_MUTEX(ftrace_regex_lock);
struct ftrace_page {
@ -988,6 +986,8 @@ struct ftrace_page {
int size;
};
static struct ftrace_page *ftrace_new_pgs;
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
#define ENTRIES_PER_PAGE (PAGE_SIZE / ENTRY_SIZE)
@ -1445,8 +1445,6 @@ ftrace_record_ip(unsigned long ip)
return NULL;
rec->ip = ip;
rec->newlist = ftrace_new_addrs;
ftrace_new_addrs = rec;
return rec;
}
@ -1936,9 +1934,11 @@ static int ops_traces_mod(struct ftrace_ops *ops)
static int ftrace_update_code(struct module *mod)
{
struct ftrace_page *pg;
struct dyn_ftrace *p;
cycle_t start, stop;
unsigned long ref = 0;
int i;
/*
* When adding a module, we need to check if tracers are
@ -1960,41 +1960,44 @@ static int ftrace_update_code(struct module *mod)
start = ftrace_now(raw_smp_processor_id());
ftrace_update_cnt = 0;
while (ftrace_new_addrs) {
for (pg = ftrace_new_pgs; pg; pg = pg->next) {
/* If something went wrong, bail without enabling anything */
if (unlikely(ftrace_disabled))
return -1;
for (i = 0; i < pg->index; i++) {
/* If something went wrong, bail without enabling anything */
if (unlikely(ftrace_disabled))
return -1;
p = ftrace_new_addrs;
ftrace_new_addrs = p->newlist;
p->flags = ref;
p = &pg->records[i];
p->flags = ref;
/*
* Do the initial record conversion from mcount jump
* to the NOP instructions.
*/
if (!ftrace_code_disable(mod, p))
break;
/*
* Do the initial record conversion from mcount jump
* to the NOP instructions.
*/
if (!ftrace_code_disable(mod, p))
break;
ftrace_update_cnt++;
ftrace_update_cnt++;
/*
* If the tracing is enabled, go ahead and enable the record.
*
* The reason not to enable the record immediatelly is the
* inherent check of ftrace_make_nop/ftrace_make_call for
* correct previous instructions. Making first the NOP
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*/
if (ftrace_start_up && ref) {
int failed = __ftrace_replace_code(p, 1);
if (failed)
ftrace_bug(failed, p->ip);
/*
* If the tracing is enabled, go ahead and enable the record.
*
* The reason not to enable the record immediatelly is the
* inherent check of ftrace_make_nop/ftrace_make_call for
* correct previous instructions. Making first the NOP
* conversion puts the module to the correct state, thus
* passing the ftrace_make_call check.
*/
if (ftrace_start_up && ref) {
int failed = __ftrace_replace_code(p, 1);
if (failed)
ftrace_bug(failed, p->ip);
}
}
}
ftrace_new_pgs = NULL;
stop = ftrace_now(raw_smp_processor_id());
ftrace_update_time = stop - start;
ftrace_update_tot_cnt += ftrace_update_cnt;
@ -3632,6 +3635,9 @@ static int ftrace_process_locs(struct module *mod,
break;
}
/* These new locations need to be initialized */
ftrace_new_pgs = pg;
/*
* We only need to disable interrupts on start up
* because we are modifying code that an interrupt