The Linux Kernel Mailing List
 help / color / mirror / Atom feed
From: "Paul E. McKenney" <paulmck@kernel.org>
To: frederic@kernel.org, rcu@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com,
	rostedt@goodmis.org, "Paul E. McKenney" <paulmck@kernel.org>
Subject: [PATCH rcu 3/5] refscale: Correct affinity check
Date: Wed,  9 Oct 2024 11:02:51 -0700	[thread overview]
Message-ID: <20241009180253.777965-3-paulmck@kernel.org> (raw)
In-Reply-To: <51cccc37-5139-497c-92e3-6a20e17939a1@paulmck-laptop>

The current affinity check works fine until there are more reader
processes than CPUs, at which point the affinity check is looking for
non-existent CPUs.  This commit therefore applies the same modulus to
the check as is present in the set_cpus_allowed_ptr() call.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/refscale.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c
index 639d1cfc657b2..af32331ef645a 100644
--- a/kernel/rcu/refscale.c
+++ b/kernel/rcu/refscale.c
@@ -863,7 +863,7 @@ ref_scale_reader(void *arg)
 		goto end;
 
 	// Make sure that the CPU is affinitized appropriately during testing.
-	WARN_ON_ONCE(raw_smp_processor_id() != me);
+	WARN_ON_ONCE(raw_smp_processor_id() != me % nr_cpu_ids);
 
 	WRITE_ONCE(rt->start_reader, 0);
 	if (!atomic_dec_return(&n_started))
-- 
2.40.1


  parent reply	other threads:[~2024-10-09 18:02 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-09 18:02 [PATCH rcu 0/5] Torture-test changes for v6.13 Paul E. McKenney
2024-10-09 18:02 ` [PATCH rcu 1/5] refscale: Add test for sched_clock() Paul E. McKenney
2024-10-09 18:02 ` [PATCH rcu 2/5] torture: Add --no-affinity parameter to kvm.sh Paul E. McKenney
2024-10-09 18:02 ` Paul E. McKenney [this message]
2024-10-09 18:02 ` [PATCH rcu 4/5] rcuscale: Add guest_os_delay module parameter Paul E. McKenney
2024-10-09 18:02 ` [PATCH rcu 5/5] rcutorture: Avoid printing cpu=-1 for no-fault RCU boost failure Paul E. McKenney

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20241009180253.777965-3-paulmck@kernel.org \
    --to=paulmck@kernel.org \
    --cc=frederic@kernel.org \
    --cc=kernel-team@meta.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rcu@vger.kernel.org \
    --cc=rostedt@goodmis.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox