linux-kernel - [RFC PATCH 1/1] ppc/smp: Replace unnecessary 'while' by 'if'

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Message-Id: <20200326203752.497029-1-leonardo@linux.ibm.com>
Date:   Thu, 26 Mar 2020 17:37:52 -0300
From:   Leonardo Bras <leonardo@...ux.ibm.com>
To:     Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Paul Mackerras <paulus@...ba.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Leonardo Bras <leonardo@...ux.ibm.com>,
        Allison Randal <allison@...utok.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     linuxppc-dev@...ts.ozlabs.org, linux-kernel@...r.kernel.org
Subject: [RFC PATCH 1/1] ppc/smp: Replace unnecessary 'while' by 'if'

spin_until_cond() will wait until nmi_ipi_busy == false, and
nmi_ipi_lock_start() does not seem to change nmi_ipi_busy, so there is
no way this while will ever repeat.

Replace this 'while' by an 'if', so it does not look like it can repeat.

Signed-off-by: Leonardo Bras <leonardo@...ux.ibm.com>
---
 arch/powerpc/kernel/smp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ea6adbf6a221..7c904d6fb4d2 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -473,7 +473,7 @@ static int __smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *),
 		return 0;
 
 	nmi_ipi_lock_start(&flags);
-	while (nmi_ipi_busy) {
+	if (nmi_ipi_busy) {
 		nmi_ipi_unlock_end(&flags);
 		spin_until_cond(!nmi_ipi_busy);
 		nmi_ipi_lock_start(&flags);
-- 
2.24.1