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| author | cpw@sgi.com <cpw@sgi.com> | 2011-06-21 14:21:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-06-21 14:50:31 +0200 |
| commit | 00b30cf04a775b5292ab704f782394e36e25617d (patch) | |
| tree | f32ed307eb07b5aca3130e99f4479ed6f4e736b5 /arch/x86 | |
| parent | x66, UV: Enable 64-bit ACPI MFCG support for SGI UV2 platform (diff) | |
| download | linux-00b30cf04a775b5292ab704f782394e36e25617d.tar.xz linux-00b30cf04a775b5292ab704f782394e36e25617d.zip | |
x86, UV: Fix smp_processor_id() use in a preemptable region
Fix a call by tunables_write() to smp_processor_id() within a
preemptable region.
Call get_cpu()/put_cpu() around the region where the returned
cpu number is actually used, which makes it non-preemptable.
A DEBUG_PREEMPT warning is prevented.
UV does not support cpu hotplug yet, but this is a step toward
that ability as well.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.086384966@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/platform/uv/tlb_uv.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/platform/uv/tlb_uv.c b/arch/x86/platform/uv/tlb_uv.c index 68e467f69fec..34be65093309 100644 --- a/arch/x86/platform/uv/tlb_uv.c +++ b/arch/x86/platform/uv/tlb_uv.c @@ -1334,9 +1334,10 @@ static ssize_t tunables_write(struct file *file, const char __user *user, instr[count] = '\0'; - bcp = &per_cpu(bau_control, smp_processor_id()); - + cpu = get_cpu(); + bcp = &per_cpu(bau_control, cpu); ret = parse_tunables_write(bcp, instr, count); + put_cpu(); if (ret) return ret; |