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From: Arnd Bergmann <arnd@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>,
	Tejun Heo <tj@kernel.org>, Breno Leitao <leitao@debian.org>
Cc: Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org
Subject: [PATCH] workqueue: avoid unguarded 64-bit division
Date: Thu,  2 Apr 2026 22:59:03 +0200	[thread overview]
Message-ID: <20260402205913.1953402-1-arnd@kernel.org> (raw)

From: Arnd Bergmann <arnd@arndb.de>

The printk() requires a division that is not allowed on 32-bit architectures:

x86_64-linux-ld: lib/test_workqueue.o: in function `test_workqueue_init':
test_workqueue.c:(.init.text+0x36f): undefined reference to `__udivdi3'

Use div_u64() to print the resulting elapsed microseconds.

Fixes: 24b2e73f9700 ("workqueue: add test_workqueue benchmark module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 lib/test_workqueue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/test_workqueue.c b/lib/test_workqueue.c
index f2ae1ac4bd93..99e160bd5ad1 100644
--- a/lib/test_workqueue.c
+++ b/lib/test_workqueue.c
@@ -242,7 +242,7 @@ static int __init run_bench(int n_threads, const char *scope, const char *label)
 
 	pr_info("test_workqueue:   %-16s %llu items/sec\tp50=%llu\tp90=%llu\tp95=%llu ns\n",
 		label,
-		elapsed_us ? total_items * 1000000ULL / elapsed_us : 0,
+		elapsed_us ? div_u64(total_items * 1000000ULL, elapsed_us) : 0,
 		all_latencies[total_items * 50 / 100],
 		all_latencies[total_items * 90 / 100],
 		all_latencies[total_items * 95 / 100]);
-- 
2.39.5


             reply	other threads:[~2026-04-02 20:59 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-02 20:59 Arnd Bergmann [this message]
2026-04-03 17:50 ` [PATCH] workqueue: avoid unguarded 64-bit division Tejun Heo
2026-04-07 14:03 ` Breno Leitao

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