Messages in this thread | | | Date | Wed, 14 Oct 2020 11:38:23 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] ring-buffer: Add rb_check_bpage in __rb_allocate_pages |
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On Wed, 14 Oct 2020 23:16:14 +0800 Qiujun Huang <hqjagain@gmail.com> wrote:
> It may be better to check each page is aligned by 4 bytes. The 2 > least significant bits of the address will be used as flags. > > Signed-off-by: Qiujun Huang <hqjagain@gmail.com> > --- > kernel/trace/ring_buffer.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 93ef0ab6ea20..9dec7d58b177 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -1420,7 +1420,8 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) > return 0; > } > > -static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) > +static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, > + long nr_pages, struct list_head *pages, int cpu) > { > struct buffer_page *bpage, *tmp; > bool user_thread = current->mm != NULL; > @@ -1464,6 +1465,8 @@ static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) > if (!bpage) > goto free_pages; > > + rb_check_bpage(cpu_buffer, bpage); > + >
Why add it here, and not just add this check to the scan in rb_check_pages()?
-- Steve
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