Re: [PATCH] net: tcp: Fix a PTO timing granularity issue

[Eric Dumazet]

On Wed, 2015-05-27 at 10:40 -0400, Ido Yariv wrote:

> HZ=100 is used on some embedded platforms, so it's still something we
> have to deal with unfortunately..
> 
> Since the '2' here is a lower bound, and msecs_to_jiffies(10) will
> return values greater than 2 for HZ>100 anyway, always ensuring the
> 2 jiffies lower bound shouldn't impact the behavior when HZ=1000.
> 
> However, as far as I can tell, comparing msecs_to_jiffies(10) to 2, or
> comparing the whole timeout to 2 doesn't make much difference, since
> msecs_to_jiffies isn't inlined.
> 
> In other words, keeping the #if shouldn't make much difference in behavior,
> but will save the small comparison.

Yes, I guess David point is to have a macro in include/linux/tcp.h so
that we can have a nice comment, and not having #if ... in a C file.

Maybe other timers in TCP need the same care (I am not asking you to
find them, but having a macro would ease things perhaps)



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/