From: Steven Rostedt (VMware) Date: Thu, 1 Apr 2021 20:40:32 +0000 (-0400) Subject: ftrace: Simplify the calculation of page number for ftrace_page->records some more X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ceaaa12904df07d07ea8975abbf04c4d60e46956;p=linux.git ftrace: Simplify the calculation of page number for ftrace_page->records some more 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+gQ@mail.gmail.com/ Suggested-by: Linus Torvalds Signed-off-by: Steven Rostedt (VMware) --- diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f7bef5a9ada97..057e962ca5ce4 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);