diff options
| author | Wei Yang | 2020-08-31 11:11:02 +0800 |
|---|---|---|
| committer | Steven Rostedt (VMware) | 2020-10-08 15:29:06 -0400 |
| commit | b40c6eabfcd409e022fcb377ac268e3ef9446fde (patch) | |
| tree | 9f5cf98fcd3a13f2951d7d2b8c0cc12ffec45738 | |
| parent | 02dae28f0b542969e44cbc1e14ffc9944cd2975c (diff) | |
ftrace: Simplify the calculation of page number for ftrace_page->records
Based on the following two reasones, we could simplify the calculation:
- If the number after roundup count is not power of 2, we would
definitely have more than 1 empty page with a higher order.
- get_count_order() just return current order, so one lower order
could meet the requirement.
The calculation could be simplified by lower one order level when pages
are not power of 2.
Link: https://lkml.kernel.org/r/20200831031104.23322-5-richard.weiyang@linux.alibaba.com
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/ftrace.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index c51a91aea1fd..c3be18b4f27b 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3129,18 +3129,19 @@ static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs) static int ftrace_allocate_records(struct ftrace_page *pg, int count) { int order; - int cnt; + int pages, cnt; if (WARN_ON(!count)) return -EINVAL; - order = get_count_order(DIV_ROUND_UP(count, ENTRIES_PER_PAGE)); + pages = DIV_ROUND_UP(count, ENTRIES_PER_PAGE); + order = get_count_order(pages); /* * We want to fill as much as possible. No more than a page * may be empty. */ - while ((PAGE_SIZE << order) / ENTRY_SIZE >= count + ENTRIES_PER_PAGE) + if (!is_power_of_2(pages)) order--; again: |