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| author | Mathias Krause <minipli@googlemail.com> | 2017-09-08 20:57:09 +0200 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2020-05-22 21:19:12 +0100 |
| commit | b094ba4b6794c2ede4a1e00fd927df604aaba960 (patch) | |
| tree | 4853f1fa92b23149d3a019383028818bd0d553fa | |
| parent | 51cc7091b3cb99ea5a2f2837c310e73e2a9d9b01 (diff) | |
| download | linux-stable-b094ba4b6794c2ede4a1e00fd927df604aaba960.tar.gz | |
padata: set cpu_index of unused CPUs to -1
commit 1bd845bcb41d5b7f83745e0cb99273eb376f2ec5 upstream.
The parallel queue per-cpu data structure gets initialized only for CPUs
in the 'pcpu' CPU mask set. This is not sufficient as the reorder timer
may run on a different CPU and might wrongly decide it's the target CPU
for the next reorder item as per-cpu memory gets memset(0) and we might
be waiting for the first CPU in cpumask.pcpu, i.e. cpu_index 0.
Make the '__this_cpu_read(pd->pqueue->cpu_index) == next_queue->cpu_index'
compare in padata_get_next() fail in this case by initializing the
cpu_index member of all per-cpu parallel queues. Use -1 for unused ones.
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | kernel/padata.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/padata.c b/kernel/padata.c index 8b95e318408d23..26feec13f0283f 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -395,8 +395,14 @@ static void padata_init_pqueues(struct parallel_data *pd) struct padata_parallel_queue *pqueue; cpu_index = 0; - for_each_cpu(cpu, pd->cpumask.pcpu) { + for_each_possible_cpu(cpu) { pqueue = per_cpu_ptr(pd->pqueue, cpu); + + if (!cpumask_test_cpu(cpu, pd->cpumask.pcpu)) { + pqueue->cpu_index = -1; + continue; + } + pqueue->pd = pd; pqueue->cpu_index = cpu_index; cpu_index++; |