On Fri, Oct 04, 2019 at 07:49:10PM +0000, Stefan Reiter wrote:
> Commit 18cd8c93e69e ("rcu/nocb: Print gp/cb kthread hierarchy if
> dump_tree") added print statements to rcu_organize_nocb_kthreads for
> debugging, but incorrectly guarded them, causing the function to always
> spew out its message.
>
> This patch fixes it by guarding both pr_alert statements with dump_tree,
> while also changing the second pr_alert to a pr_cont, to print the
> hierarchy in a single line (assuming that's how it was supposed to
> work).
>
> Fixes: 18cd8c93e69e ("rcu/nocb: Print gp/cb kthread hierarchy if dump_tree")
> Signed-off-by: Stefan Reiter <stefan@xxxxxxxxxx>
Queued for testing and review, thank you!
> ---
>
> First time contributing to the kernel, hope I'm doing this right :)
Looks good so far. Then again, I just kicked off the tests. ;-)
Thanx, Paul
> kernel/rcu/tree_plugin.h | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index 2defc7fe74c3..7cbf4a0f3eff 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -2346,15 +2346,19 @@ static void __init rcu_organize_nocb_kthreads(void)
> nl = DIV_ROUND_UP(rdp->cpu + 1, ls) * ls;
> rdp->nocb_gp_rdp = rdp;
> rdp_gp = rdp;
> - if (!firsttime && dump_tree)
> - pr_cont("\n");
> - firsttime = false;
> - pr_alert("%s: No-CB GP kthread CPU %d:", __func__, cpu);
> + if (dump_tree) {
> + if (!firsttime)
> + pr_cont("\n");
> + firsttime = false;
> + pr_alert("%s: No-CB GP kthread CPU %d:",
> + __func__, cpu);
> + }
> } else {
> /* Another CB kthread, link to previous GP kthread. */
> rdp->nocb_gp_rdp = rdp_gp;
> rdp_prev->nocb_next_cb_rdp = rdp;
> - pr_alert(" %d", cpu);
> + if (dump_tree)
> + pr_cont(" %d", cpu);
> }
> rdp_prev = rdp;
> }
> --
> 2.23.0
>
>
