Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3

Ingo Molnar
2007-02-25T18:01:13Z

* Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:

> > hm, what tree are you using as a base? The syslet patches are
> > against v2.6.20 at the moment. (the x86 PDA changes will probably
> > interfere with it on v2.6.21-rc1-ish kernels) Note that otherwise
> > the syslet/threadlet patches are for x86 only at the moment (as i
> > mentioned in the announcement), and the generic code itself contains
> > some occasional x86-ishms as well. (None of the concepts are
> > x86-specific though - multi-stack architectures should work just as
> > well as RISC-ish CPUs.)
>
> It is rc1 - and crashes.

yeah. I'm not surprised. The PDA is not set up in create_async_thread()
for example.

> > if you create a threadlet based test-webserver, could you please do
> > a comparable kevents implementation as well? I.e. same HTTP parser
> > (or non-parser, as usually the case is with prototypes ;). Best
> > would be something that one could trigger between threadlet and
> > kevent mode, using the same binary :-)
>
> Ok, I will create such a monster tomorrow :)
>
> I will use the same base for threadlet as for kevent/epoll - there is
> no parser, just sendfile() of the static file which contains http
> header and actual page.
>
> threadlet1 {
> accept()
> create threadlet2 {
> send data
> }
> }
>
> Is above scheme correct for threadlet scenario?

yep, this is a good first cut. Doing this after the listen() is useful:

int one = 1;

ret = setsockopt(listen_sock_fd, SOL_SOCKET, SO_REUSEADDR,
(char *)&one, sizeof(int));

and i'd suggest to do this after every accept()-ed socket:

int flag = 1;

setsockopt(sock_fd, IPPROTO_TCP, TCP_NODELAY,
(char *) &flag, sizeof(int));

Do you have any link where i could check the type of HTTP parsing and
send transport you are (or will be) using? What type of http client are
you using to measure, with precisely what options?

> But note, that on my athlon64 3500 test machine kevent is about 7900
> requests per second compared to 4000+ epoll, so expect a challenge.

single-core CPU i suspect?

> lighhtpd is about the same 4000 requests per second though, since it
> can not be easily optimized for kevents.

mean question: do you promise to post the results even if they are not
unfavorable to threadlets? ;-)

if i want to test kevents on a v2.6.20 kernel base, do you have an URL
for me to try?

Ingo