lkml.org 
[lkml]   [1999]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Linus on Linux, Apache and Threads
On Sat, Apr 24, 1999 at 02:35:59PM +0200, Alex Belits wrote:
> On 24 Apr 1999, Andi Kleen wrote:
>
> >
> > You have multiple threads doing an accept on a single listen socket. As
> > soon as a thread finished work it calls accept and gets the next ready
> > connection handed from the kernel.
>
> ...or will be awakened on the connection that was handled by another
> thread (because of "wake everyone" handling), and accept() will fail,
> causing the infamous "thundering herd".

If the load is high enough it doesn't matter, because there will
be always enough connections to be returned to an accept after a wakeup.
If it isn't the threads pool should adapt and use less threads which
avoids the problem (and a few lost wakeups in the transitions don't harm,
because the machine has enough free cycles).

Do you have any real data that this doesn't happen?

-Andi
--
This is like TV. I don't like TV.

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

\
 
 \ /
  Last update: 2005-03-22 13:51    [W:0.133 / U:0.552 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site