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authorArnd Bergmann <[email protected]>2018-07-09 10:34:43 +0200
committerJason Gunthorpe <[email protected]>2018-07-11 12:10:19 -0600
commit07f3355df7e6d043d36d4c172a18e74510fe7e7b (patch)
treeaf9dd5aec8f33edaa2c88caa964d136f513ffc83 /tools/perf/util/scripting-engines/trace-event-python.c
parent59b851dbf7dc94214e4fab5dd29ea28b4075a04f (diff)
infiniband: i40iw, nes: don't use wall time for TCP sequence numbers
The nes infiniband driver uses current_kernel_time() to get a nanosecond granunarity timestamp to initialize its tcp sequence counters. This is one of only a few remaining users of that deprecated function, so we should try to get rid of it. Aside from using a deprecated API, there are several problems I see here: - Using a CLOCK_REALTIME based time source makes it predictable in case the time base is synchronized. - Using a coarse timestamp means it only gets updated once per jiffie, making it even more predictable in order to avoid having to access the hardware clock source - The upper 2 bits are always zero because the nanoseconds are at most 999999999. For the Linux TCP implementation, we use secure_tcp_seq(), which appears to be appropriate here as well, and solves all the above problems. i40iw uses a variant of the same code, so I do that same thing there for ipv4. Unlike nes, i40e also supports ipv6, which needs to call secure_tcpv6_seq instead. Acked-by: Shiraz Saleem <[email protected]> Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]>
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