On 22.10.2015 23:37, Tom Herbert wrote: > On Thu, Oct 22, 2015 at 1:00 PM, Helge Deller <deller@xxxxxx> wrote: >> Hi Tom & David, >> >> I've queued-up a patch for the parisc architecture which reduces L1_CACHE_BYTES from 32 to 16: >> https://patchwork.kernel.org/patch/7399291/ >> >> But this change will break the kernel build like this: >> >> In file included from net/core/dev.c:92:0: >> net/core/dev.c: In function ‘expand_xps_map’: >> include/linux/netdevice.h:721:27: warning: overflow in implicit constant conversion [-Woverflow] >> #define XPS_MIN_MAP_ALLOC ((L1_CACHE_BYTES - sizeof(struct xps_map)) \ >> net/core/dev.c:1972:18: note: in expansion of macro ‘XPS_MIN_MAP_ALLOC’ >> int alloc_len = XPS_MIN_MAP_ALLOC; >> >> Do you see an easy way to fix this ? >> > How about > > #define XPS_MIN_MAP_ALLOC ((L1_CACHE_BYTES - ((sizeof(struct xps_map) > % L1_CACHE_BYTES)) \ The full line would then be: #define XPS_MIN_MAP_ALLOC ((L1_CACHE_BYTES - (sizeof(struct xps_map) % L1_CACHE_BYTES)) / sizeof(u16)) The only problem I see with this is, that XPS_MIN_MAP_ALLOC might become zero. In that case the call to kzalloc_node() in expand_xps_map() doesn't allocate any memory for the queues. Helge -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
