Messages in this thread | | | Date | Fri, 13 Oct 2023 11:22:03 -0400 | From | Daniel Jordan <> | Subject | Re: [PATCH v3] Fixes: 07928d9bfc81 ("padata: Remove broken queue flushing") |
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Hi,
On Sat, Oct 07, 2023 at 11:52:33AM +0800, Wang Jinchao wrote: > Signed-off-by: Wang Jinchao <wangjinchao@xfusion.com>
The Fixes: tag should be near your Signed-off-by:, and the subject of the patch should be something descriptive like
padata: Fix refcnt handling in padata_free_shell()
Here's some documentation about this:
https://docs.kernel.org/process/5.Posting.html#patch-formatting-and-changelogs
> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> > --- > V3: > Include Daniel's ack > > V2: https://lore.kernel.org/all/ZRTLHY5A+VqIKhA2@fedora/ > To satisfy Sparse, use rcu_dereference_protected. > Reported-by: kernel test robot <lkp@intel.com> > Closes: https://lore.kernel.org/oe-kbuild-all/202309270829.xHgTOMKw-lkp@intel.com/
These two tags can also go near your SoB.
> V1: https://lore.kernel.org/all/ZRE4XvOOhz4HSOgR@fedora/ > > kernel/padata.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/kernel/padata.c b/kernel/padata.c > index 222d60195de6..79d04a97ded6 100644 > --- a/kernel/padata.c > +++ b/kernel/padata.c > @@ -1102,12 +1102,16 @@ EXPORT_SYMBOL(padata_alloc_shell); > */ > void padata_free_shell(struct padata_shell *ps) > { > + struct parallel_data *pd; > + > if (!ps) > return; > > mutex_lock(&ps->pinst->lock); > list_del(&ps->list); > - padata_free_pd(rcu_dereference_protected(ps->pd, 1)); > + pd = rcu_dereference_protected(ps->pd, 1); > + if (refcount_dec_and_test(&pd->refcnt)) > + padata_free_pd(rcu_dereference_protected(ps->pd, 1));
As Herbert points out, this version changes the code by rcu-dereferencing pd twice. Usually previous acks are dropped when introducing new changes, but you can have it back by only rcu-dereferencing once and addressing the other comments above.
> mutex_unlock(&ps->pinst->lock); > > kfree(ps); > -- > 2.40.0 >
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