Messages in this thread | | | Subject | Re: [PATCH v2] async: Let kfree() out of the critical area of the lock | From | Yunfeng Ye <> | Date | Tue, 19 Nov 2019 11:01:15 +0800 |
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On 2019/11/16 2:32, Thomas Gleixner wrote: > > > On Fri, 11 Oct 2019, Yunfeng Ye wrote: > >> The async_lock is big global lock, and kfree() is not always cheap, it >> will increase lock contention. it's better let kfree() outside the lock >> to keep the critical area as short as possible. >> >> Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com> >> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> >> Reviewed-by: Bart Van Assche <bvanassche@acm.org> >> --- >> v1 -> v2: >> - update the description >> - add "Reviewed-by" >> >> kernel/async.c | 6 +++--- >> 1 file changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/kernel/async.c b/kernel/async.c >> index 4f9c1d6..1de270d 100644 >> --- a/kernel/async.c >> +++ b/kernel/async.c >> @@ -135,12 +135,12 @@ static void async_run_entry_fn(struct work_struct *work) >> list_del_init(&entry->domain_list); >> list_del_init(&entry->global_list); >> >> - /* 3) free the entry */ >> - kfree(entry); >> atomic_dec(&entry_count); >> - >> spin_unlock_irqrestore(&async_lock, flags); >> >> + /* 3) free the entry */ >> + kfree(entry); >> + >> /* 4) wake up any waiters */ >> wake_up(&async_done); > > The wakeup should happen before the kfree() for the very same reasons. > ok, I will modify as your suggest, thanks.
> Thanks, > > tglx > > . >
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