From: jamal <[EMAIL PROTECTED]> Date: Sun, 16 Sep 2007 12:14:34 -0400
> Changes: > I made changes to the code path as defined in the patch included to > and noticed a slight increase (2-3%) in performance with both e1000 and > tg3; which was a relief because i thought the spinlock_irq (which is > needed because some drivers grab tx lock in interupts) may have negative > effects. The fact it didnt reduce performance was a good thing. > Note: This is the highest end machine ive ever laid hands on, so this > may be misleading. > > So - what side effects do people see in doing this? If none, i will > clean it up and submit. I tried this 4 years ago, it doesn't work. :-) Many drivers, particularly very old ones that PIO packets into a device which can take a long time, absolutely depend upon interrupts being enabled fully during ->hard_start_xmit() so that other high periority devices (such as simpler serial controllers) can have their interrupts serviced during this slow operation. I don't think we want to do it anyways, whatever performance we gain from it is offset by the badness of disabling interrupts during this reasonably length stretch of code. The -rt folks as a result would notice this too and spank us :-) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html