Messages in this thread | | | Date | Thu, 20 Apr 2006 16:01:31 -0700 | From | Andrew Morton <> | Subject | Re: [Patch: 003/006] pgdat allocation for new node add (generic alloc node_data) |
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Yasunori Goto <y-goto@jp.fujitsu.com> wrote: > > +#define generic_alloc_nodedata(nid) \ > +({ \ > + (pg_data_t *)kzalloc(sizeof(pg_data_t), GFP_KERNEL); \ > +})
In general, library functions which perform memory allocation should not make assumptions about which gfp_t they are allowed to use.
So this really should be `generic_alloc_nodedata(nid, gfp_mask)'.
However, it's very desirable that memory allocations use GFP_KERNEL rather than, say, GFP_ATOMIC. So your interface here _forces_ callers to be in a state where GFP_KERNEL is legal, which is good discipline.
Although if that turns out to be a problem, we can expect to see a sad little patch from someone which tries to change this to GFP_ATOMIC, which makes everything worse - even those callers who _can_ use GFP_KERNEL.
(In practice, NUMA developers seem to never test with sufficient CONFIG_DEBUG_* flags enabled, and with CONFIG_PREEMPT, so they happily don't get to discover their sleep-in-spinlock bugs anyway).
Anyway, on balance, I think it'd be best to convert this API to take a gfp_t as well.
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