From: Valentin Schneider <vschneid@redhat.com>
To: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Jens Axboe <axboe@kernel.dk>, Yury Norov <yury.norov@gmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: [RFC PATCH bitmap-for-next 2/4] lib/cpumask: Fix cpumask_check() warning in cpumask_next_wrap*()
Date: Thu, 6 Oct 2022 13:21:10 +0100 [thread overview]
Message-ID: <20221006122112.663119-3-vschneid@redhat.com> (raw)
In-Reply-To: <20221006122112.663119-1-vschneid@redhat.com>
Invoking cpumask_next*() with n==nr_cpu_ids-1 triggers a warning as there
are (obviously) no more valid CPU ids after that. This is however undesired
for the cpumask_next_wrap*() family which needs to wrap around reaching
this condition.
Don't invoke cpumask_next*() when n==nr_cpu_ids, go for the wrapping (if
any) instead.
NOTE: this only fixes the NR_CPUS>1 variants.
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
---
lib/cpumask.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/cpumask.c b/lib/cpumask.c
index 6e576485c84f..f8174fa3d752 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -12,11 +12,11 @@
unsigned int next; \
\
again: \
- next = (FETCH_NEXT); \
+ next = n == nr_cpu_ids - 1 ? nr_cpu_ids : (FETCH_NEXT); \
\
if (wrap && n < start && next >= start) { \
- next = nr_cpumask_bits; \
- } else if (next >= nr_cpumask_bits) { \
+ next = nr_cpu_ids; \
+ } else if (next >= nr_cpu_ids) { \
wrap = true; \
n = -1; \
goto again; \
--
2.31.1
next prev parent reply other threads:[~2022-10-06 12:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-06 12:21 [RFC PATCH bitmap-for-next 0/4] lib/cpumask, blk_mq: Fix blk_mq_hctx_next_cpu() vs cpumask_check() Valentin Schneider
2022-10-06 12:21 ` [RFC PATCH bitmap-for-next 1/4] lib/cpumask: Generate cpumask_next_wrap() body with a macro Valentin Schneider
2022-10-06 12:21 ` Valentin Schneider [this message]
2022-10-06 12:21 ` [RFC PATCH bitmap-for-next 3/4] lib/cpumask: Introduce cpumask_next_and_wrap() Valentin Schneider
2022-10-06 12:21 ` [RFC PATCH bitmap-for-next 4/4] blk_mq: Fix cpumask_check() warning in blk_mq_hctx_next_cpu() Valentin Schneider
2022-10-06 13:50 ` Yury Norov
2022-10-06 15:17 ` Valentin Schneider
2022-10-07 5:15 ` Yury Norov
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