Re: [PATCH v2] mac80211_hwsim: don't use WQ_MEM_RECLAIM

[Arend van Spriel <arend.vanspriel@broadcom.com>]

resending as it included html and got blocked from the list.

On 1/25/2018 7:21 PM, Arend Van Spriel wrote:
> Op 24 jan. 2018 11:46 schreef "Johannes Berg" <johannes@sipsolutions.net
> <mailto:johannes@sipsolutions.net>>:
>  >
>  > On Wed, 2018-01-24 at 10:39 +0100, Benjamin Beichler wrote:
>  >
>  > > sorry for introducing that error, but I'm a bit confused by the
>  > > workqueue documentation.
>  > > My assumption was, that deleting hwsim radios is reclaiming memory, and
>  > > since this queue does nothing else it would save/necessary to set
> this flag.
>  > >
>  > > Maybe a hint in the documentation, that a work item on a WQ_MEM_RECLAIM
>  > > queue must not call flush of an !WQ_MEM_RECLAIM queue would be nice.
>  > > Maybe it's kind of obvious, but there is also a reminder not to forget
>  > > that flag, if a queue may have work items that reclaim memory
>  >
>  > Yeah, honestly, I'm not really sure either. Clearly we can't set it,
>  > but other drivers also set it...
>
> That triggered something in my memory. So indeed we use it in brcmfmac
> as well. We used create_singlethread_workqueue(), but I wanted to avoid
> snprintf and specify the name format so switched to using
> alloc_ordered_workqueue() keeping WQ_MEM_RECLAIM as per the macro
> definition.

#define create_singlethread_workqueue(name)				\
	alloc_ordered_workqueue("%s", __WQ_LEGACY | WQ_MEM_RECLAIM, name)

> Don't recall why I dropped the __WQ_LEGACY flag though.
>
> Regards,
> Arend
>
>  > I don't think it was *intended* for when you're freeing memory, since I
>  > think reclaiming is what happens when you write out dirty buffers to
>  > disk etc.
>  >
>  > johannes
>