Messages in this thread | | | Date | Tue, 13 Aug 2013 16:45:44 +0900 | From | Joonsoo Kim <> | Subject | Re: [PATCH v2 09/20] mm, hugetlb: protect region tracking via newly introduced resv_map lock |
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> > @@ -202,15 +199,27 @@ static long region_chg(struct resv_map *resv, long f, long t) > > * Subtle, allocate a new region at the position but make it zero > > * size such that we can guarantee to record the reservation. */ > > if (&rg->link == head || t < rg->from) { > > - nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); > > - if (!nrg) > > - return -ENOMEM; > > + if (!nrg) { > > + nrg = kmalloc(sizeof(*nrg), GFP_NOWAIT); > > + if (!nrg) { > > + spin_unlock(&resv->lock); > > + nrg = kmalloc(sizeof(*nrg), GFP_KERNEL); > > + if (!nrg) { > > + chg = -ENOMEM; > > + goto out; > > Just return -ENOMEM here.
Okay. It looks better!
> > > + } > > + goto retry; > > + } > > + } > > + > > You seem to be right, at least in my workloads, the hold times for the > region lock is quite small, so a spinlock is better than a sleeping > lock. > > That said, this code is quite messy, but I cannot think of a > better/cleaner approach right now.
Okay.
Thanks for review!
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