linux-kernel - [PATCH] x86: Put the num_processors++ code in a more suitable position

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Date:   Tue, 6 Sep 2016 13:31:27 +0800
From:   Dou Liyang <douly.fnst@...fujitsu.com>
To:     <linux-kernel@...r.kernel.org>
CC:     <x86@...nel.org>, <tglx@...utronix.de>, <mingo@...hat.com>,
        <hpa@...or.com>, Dou Liyang <douly.fnst@...fujitsu.com>
Subject: [PATCH] x86: Put the num_processors++ code in a more suitable position

This is a code optimization.

If checking the topology package map of apicid and cpu is failure,
it will stop generating the processor info for that apicid and the
disabled_cpus will plus one. However, the num-processors has already
been added one above. That may cause the number of processors incorrect.

Just put the num_processors++ code in the more suitable position.
it makes sure that the num-processors will not conflict with the
disabled_cpus.

Signed-off-by: Dou Liyang <douly.fnst@...fujitsu.com>
---
 arch/x86/kernel/apic/apic.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 50c95af..f3e9b2d 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2093,7 +2093,6 @@ int generic_processor_info(int apicid, int version)
 		return -EINVAL;
 	}

-	num_processors++;
 	if (apicid == boot_cpu_physical_apicid) {
 		/*
 		 * x86_bios_cpu_apicid is required to have processors listed
@@ -2116,10 +2115,13 @@ int generic_processor_info(int apicid, int version)

 		pr_warning("APIC: Package limit reached. Processor %d/0x%x ignored.\n",
 			   thiscpu, apicid);
+
 		disabled_cpus++;
 		return -ENOSPC;
 	}

+	num_processors++;
+
 	/*
 	 * Validate version
 	 */
-- 
2.5.5