Dear folks, For my LG-NAS, a Marvell based board, the DMA controller is working and i can get a rough 27 Mb/sec reading directory trees from the disc in FFS and around 90 to 100 Mb/sec from the raw partiton to /dev/null. In these i see hardly interrupt time but lots of system time, around 70-80% and some 10-15% idle time. So DMA for the SATA is working fine! The 70-80% cpu time is most likely FFS, overhead and such and some for the /dev/null writing. If I test it from another machine and read the same set from NFS i get quite different values! The rate drops to 11 Mb/sec and the system time is around 30% but the interrupt time is 60-70%! Am I right to conclude that the Marvell Gbit ethernet controller mvgbe0 is NOT using DMA? or is it using it but also crappy in design? With regards, Reinoud
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