提交 23952a96 编写于 作者: A Andreas Herrmann 提交者: Ingo Molnar

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

Exception stacks are allocated each time a CPU is set online.
But the allocated space is never freed. Thus with one CPU hotplug
offline/online cycle there is a memory leak of 24K (6 pages) for
a CPU.

Fix is to allocate exception stacks only once -- when the CPU is
set online for the first time.
Signed-off-by: NAndreas Herrmann <andreas.herrmann3@amd.com>
Cc: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>
上级 d04ec773
......@@ -640,19 +640,22 @@ void __cpuinit cpu_init(void)
/*
* set up and load the per-CPU TSS
*/
for (v = 0; v < N_EXCEPTION_STACKS; v++) {
if (!orig_ist->ist[0]) {
static const unsigned int order[N_EXCEPTION_STACKS] = {
[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
[DEBUG_STACK - 1] = DEBUG_STACK_ORDER
[0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STACK_ORDER,
[DEBUG_STACK - 1] = DEBUG_STACK_ORDER
};
if (cpu) {
estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
if (!estacks)
panic("Cannot allocate exception stack %ld %d\n",
v, cpu);
for (v = 0; v < N_EXCEPTION_STACKS; v++) {
if (cpu) {
estacks = (char *)__get_free_pages(GFP_ATOMIC, order[v]);
if (!estacks)
panic("Cannot allocate exception "
"stack %ld %d\n", v, cpu);
}
estacks += PAGE_SIZE << order[v];
orig_ist->ist[v] = t->x86_tss.ist[v] =
(unsigned long)estacks;
}
estacks += PAGE_SIZE << order[v];
orig_ist->ist[v] = t->x86_tss.ist[v] = (unsigned long)estacks;
}
t->x86_tss.io_bitmap_base = offsetof(struct tss_struct, io_bitmap);
......
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