Messages in this thread | | | Date | Tue, 18 Oct 2011 15:38:16 +0900 | From | Tomoya MORINAGA <> | Subject | Re: gpio-ml-ioh: Support interrupt function |
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(2011/10/18 14:56), David Rientjes wrote: > On Tue, 18 Oct 2011, Tomoya MORINAGA wrote: > >>> The linux-next patch 54be566317b6 "gpio-ml-ioh: Support interrupt >>> function" generates a Sparse warning. >>> >>> + irq_base = irq_alloc_descs(-1, IOH_IRQ_BASE, num_ports[j], >>> + GFP_KERNEL); >>> ^^^^^^^^^^ >>> >>> The last argument should be a NUMA node, not a GFP_ flag. I'm not >>> sure what the right fix is. There are currently 5 callers in my >>> cscope for this function in linux-next. >>> >>> 2 pass GFP_KERNEL which is wrong. > > Right, all irq_alloc_descs() allocations are already implicitly > GFP_KERNEL. > >>> 2 pass 0 which maybe should be cpu_to_node(0)? >>> 1 passes -1 which maybe could be NUMA_NO_NODE? >>> >> I can understand your saying. >> Seeing accepted other drivers, '0' or '-1' is used. > > There's actually no guarantee in the kernel that node 0 has memory, so > unless that is assured in the context then passing 0 would be wrong. > >> Focusing on GPIO driver, gpio-pca953x.c uses '-1'. >> > > The slab layer guarantees that passing -1 will allocate on the node that > is local to the cpu that the code is running on. Unless there's a > compelling reason to allocate on a different node, then this is what you > want to use. > > We try not to pass -1 directly, though, we try to use NUMA_NO_NODE > wherever possible. >
Hi, David Thank you for your information. I will try to test with '-1'.
After testing with '-1', I will post the patch for this.
Thanks, -- tomoya ROHM Co., Ltd.
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