| Message ID | 1677112392-17332-1-git-send-email-anthony.yznaga@oracle.com |
|---|---|
| State | Accepted |
| Commit | f84155ca851849e5e8981fddd3945a6cfeea220c |
| Headers | show |
| Series | padata: use alignment when calculating the number of worker threads | expand |
On Wed, Feb 22, 2023 at 04:33:12PM -0800, Anthony Yznaga wrote: > For multithreaded jobs the computed chunk size is rounded up by the > caller-specified alignment. However, the number of worker threads to > use is computed using the minimum chunk size without taking alignment > into account. A sufficiently large alignment value can result in too > many worker threads being allocated for the job. > > Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> No effect for now since the page init code uses the same align and min_chunk, but it protects future users from this problem so Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Thanks. > --- > kernel/padata.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/padata.c b/kernel/padata.c > index e007b8a4b738..4abc536ecdb1 100644 > --- a/kernel/padata.c > +++ b/kernel/padata.c > @@ -491,7 +491,7 @@ void __init padata_do_multithreaded(struct padata_mt_job *job) > return; > > /* Ensure at least one thread when size < min_chunk. */ > - nworks = max(job->size / job->min_chunk, 1ul); > + nworks = max(job->size / max(job->min_chunk, job->align), 1ul); > nworks = min(nworks, job->max_threads); > > if (nworks == 1) { > -- > 1.8.3.1 >
diff --git a/kernel/padata.c b/kernel/padata.c index e007b8a4b738..4abc536ecdb1 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -491,7 +491,7 @@ void __init padata_do_multithreaded(struct padata_mt_job *job) return; /* Ensure at least one thread when size < min_chunk. */ - nworks = max(job->size / job->min_chunk, 1ul); + nworks = max(job->size / max(job->min_chunk, job->align), 1ul); nworks = min(nworks, job->max_threads); if (nworks == 1) {
For multithreaded jobs the computed chunk size is rounded up by the caller-specified alignment. However, the number of worker threads to use is computed using the minimum chunk size without taking alignment into account. A sufficiently large alignment value can result in too many worker threads being allocated for the job. Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- kernel/padata.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)