From: Andreas Herrmann <andreas.herrmann3@amd.com>
Date: Wed, 6 Aug 2008 08:27:30 +0000 (+0200)
Subject: x86: pda_init(): fix memory leak when using CPU hotplug
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d04ec773d7ca1bbc05a2768be95c1cebe2b07757;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

x86: pda_init(): fix memory leak when using CPU hotplug

pda->irqstackptr is allocated whenever a CPU is set online.
But it is never freed. This results in a memory leak of 16K
for each CPU offline/online cycle.

Fix is to allocate pda->irqstackptr only once.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/cpu/common_64.c b/arch/x86/kernel/cpu/common_64.c
index c3afba5a81a7..4f2eeb5652ea 100644
--- a/arch/x86/kernel/cpu/common_64.c
+++ b/arch/x86/kernel/cpu/common_64.c
@@ -529,17 +529,20 @@ void pda_init(int cpu)
 		/* others are initialized in smpboot.c */
 		pda->pcurrent = &init_task;
 		pda->irqstackptr = boot_cpu_stack;
+		pda->irqstackptr += IRQSTACKSIZE - 64;
 	} else {
-		pda->irqstackptr = (char *)
-			__get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
-		if (!pda->irqstackptr)
-			panic("cannot allocate irqstack for cpu %d", cpu);
+		if (!pda->irqstackptr) {
+			pda->irqstackptr = (char *)
+				__get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER);
+			if (!pda->irqstackptr)
+				panic("cannot allocate irqstack for cpu %d",
+				      cpu);
+			pda->irqstackptr += IRQSTACKSIZE - 64;
+		}
 
 		if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE)
 			pda->nodenumber = cpu_to_node(cpu);
 	}
-
-	pda->irqstackptr += IRQSTACKSIZE-64;
 }
 
 char boot_exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ +