Re: [PATCH] sparc: clarify __GFP_NOFAIL allocation

From: David Miller
Date: Mon Mar 02 2015 - 16:45:56 EST


From: Michal Hocko <mhocko@xxxxxxx>
Date: Mon, 2 Mar 2015 22:36:10 +0100

> 920c3ed74134 ([SPARC64]: Add basic infrastructure for MD add/remove
> notification.) has added __GFP_NOFAIL for the allocation request but
> it hasn't mentioned why is this strict requirement really needed.
> The code was handling an allocation failure and propagated it properly
> up the callchain so it is not clear why it is needed.
>
> Dave has clarified the intention when I tried to remove the flag as not
> being necessary:
> "
> It is a serious failure.
>
> If we miss an MDESC update due to this allocation failure, the update
> is not an event which gets retransmitted so we will lose the updated
> machine description forever.
>
> We really need this allocation to succeed.
> "
>
> So add a comment to clarify the nofail flag and get rid of the failure
> check because __GFP_NOFAIL allocation doesn't fail.
>
> Signed-off-by: Michal Hocko <mhocko@xxxxxxx>

Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>
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