On Fri, Feb 05, 2021 at 10:32:26AM +0000, Song Bao Hua (Barry Song) wrote:
I can keep the struct size unchanged by changing the struct to
struct map_benchmark { __u64 avg_map_100ns; /* average map latency in 100ns */ __u64 map_stddev; /* standard deviation of map latency */ __u64 avg_unmap_100ns; /* as above */ __u64 unmap_stddev; __u32 threads; /* how many threads will do map/unmap in parallel */ __u32 seconds; /* how long the test will last */ __s32 node; /* which numa node this benchmark will run on */ __u32 dma_bits; /* DMA addressing capability */ __u32 dma_dir; /* DMA data direction */ __u32 dma_trans_ns; /* time for DMA transmission in ns */
__u32 exp; /* For future use */ __u64 expansion[9]; /* For future use */ };
But the code is really ugly now.
Thats why we usually use __u8 fields for reserved field. You might consider just switching to that instead while you're at it. I guess we'll just have to get the addition into 5.11 then to make sure we don't release a kernel with the alignment fix.