From: "Steven Rostedt (VMware)" <rost...@goodmis.org> Commit b40c6eabfcd40 ("ftrace: Simplify the calculation of page number for ftrace_page->records") simplified the calculation of the number of pages needed for each page group without having any empty pages, but it can be simplified even further.
Link: https://lore.kernel.org/lkml/CAHk-=wjt9b7kxQ2J=adnkbr1qbmb3hiqb_hyczbksxgrseb...@mail.gmail.com/ Suggested-by: Linus Torvalds <torva...@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org> --- kernel/trace/ftrace.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f7bef5a9ada9..057e962ca5ce 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3156,15 +3156,9 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count) if (WARN_ON(!count)) return -EINVAL; + /* We want to fill as much as possible, with no empty pages */ 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. - */ - if (!is_power_of_2(pages)) - order--; + order = fls(pages) - 1; again: pg->records = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order); -- 2.30.1