From: "Jason A. Donenfeld" <ja...@zx2c4.com> Date: Mon, 16 Nov 2015 20:52:28 +0100
> This works fine with, say, iperf3 in TCP mode. The AVX performance > is great. However, when using iperf3 in UDP mode, irq_fpu_usable() > is mostly false! I added a dump_stack() call to see why, except > nothing looks strange; the initial call in the stack trace is > entry_SYSCALL_64_fastpath. Why would irq_fpu_usable() return false > when we're in a syscall? Doesn't that mean this is in process > context? Network device driver transmit executes with software interrupts disabled. Therefore on x86, you cannot use the FPU. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
