From: Steven Rostedt <rostedt@goodmis.org>
To: Qiujun Huang <hqjagain@gmail.com>
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] ring-buffer: Add rb_check_bpage in __rb_allocate_pages
Date: Wed, 14 Oct 2020 11:38:23 -0400 [thread overview]
Message-ID: <20201014113823.4296521d@gandalf.local.home> (raw)
In-Reply-To: <20201014151614.29804-1-hqjagain@gmail.com>
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
next prev parent reply other threads:[~2020-10-14 15:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-14 15:16 [PATCH] ring-buffer: Add rb_check_bpage in __rb_allocate_pages Qiujun Huang
2020-10-14 15:38 ` Steven Rostedt [this message]
2020-10-14 15:48 ` Qiujun Huang
2020-10-14 16:11 ` Steven Rostedt
2020-10-14 16:32 ` Qiujun Huang
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