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Hi!<br>
<br>
After fixing the patch to compile on windows[1] I put it in our
daily builds and a couple of issues came up. I did not include '<a
href="https://github.com/weicao/otp/commit/7577507ae849aa94a5cff147d8d13e7c1d327a2f"
class="message">move erts_deliver_time out of erl_check_io</a>'
commit as it deadlocks the non-smp emulator.<br>
<br>
When running a debug test build on Linux we got the following
assertion:<br>
Assertion failed: 0 <= (ix) && (ix) < erts_no_pollsets
in sys/common/erl_check_io.c, line 1909<br>
<br>
On OS X Lion we got the following when compiling gs:<br>
erl -pa ../ebin -s gs_make -s erlang halt -noshell<br>
../include/internal/ethr_mutex.h:655: Fatal error in
ethr_mutex_lock(): Invalid argument (22)<br>
make[3]: *** [gstk_generic.hrl] Abort trap: 6<br>
make[2]: *** [opt] Error 2<br>
make[1]: *** [opt] Error 2<br>
make: *** [libs] Error 2<br>
<br>
I'll remove the branch and see if the same problems appear again
tomorrow (unfortunately we do not have enough machines to let your
branch run alone, so it might be some other branch causing this).
Let me know if you need any help tracking down these issues.<br>
<br>
Lukas<br>
<br>
[1]: <a class="moz-txt-link-freetext" href="https://github.com/garazdawi/otp/tree/wc/pollset_per_scheduler">https://github.com/garazdawi/otp/tree/wc/pollset_per_scheduler</a><br>
<br>
<div class="moz-cite-prefix">On 11/07/12 17:34, Wei Cao wrote:<br>
</div>
<blockquote
cite="mid:CADS4Rawy-hVQ4BfEMbbEbyF-uC3eeyKZm2=gzNTJmZJApJWd3Q@mail.gmail.com"
type="cite">
<pre wrap="">In non keep-alive cases, all new connections 're accepted by the
Erlang port which listens on the TCP port, and how frequently/fast the
port be scheduled to run limits the QPS. (requests per second), so
this port can be regarded as bottleneck of non keep-alive
applications.
So I guess performance degradation observed is caused by the listener
port not be scheduled frequent or fast enough, I'll look into this
problem tomorrow, now is at night in China, :-)
BTW, I found this patch should be compiled like this today,
./configure CFLAGS="-DERTS_POLLSET_PER_SCHEDULER -g -O3 -fomit-frame-pointer"
otherwise compiler optimization is disabled.
Regarding binding processes/ports to scheduler, I admit it's really a
temporary solution to bind port to the same scheduler as its owner
process like the pb patch did, and I suggest it's better to add a
additional BIF like erlang:process_flag, to allow user explicitly bind
port to a given scheduler, if it benefits.
2012/7/11 Lukas Larsson <a class="moz-txt-link-rfc2396E" href="mailto:lukas@erlang.org"><lukas@erlang.org></a>:
</pre>
<blockquote type="cite">
<pre wrap="">Hi,
The reason I'm skeptical about anything which binds processes/ports to
scheduler is that it feels like a temporary solution and would much rather
do a proper solution where the scheduler takes care of these things for you.
But as I said, internally we need to talk this over when it is not in the
middle of summer vacation.
I did some benchmarking using ab and found basically the same figures as
you. The below is with keep-alive and the values are requests per second:
not-bound bound
R15B01 44k 37k
master 44k 35k
master+mp 48k 49k
master+mp+pb 49k 55k
[mp]: multi-poll patch
[pb]: port bind patch
[bound]: Used {scheduler,I} to spread load
Unfortunately I also found that when doing the non-keep alive benchmark the
performance is seriously degraded.
R15B01 not-bound 8255
master+mp+pb not-bound 7668
master+mp+pb bound 5765
I did some gprof runs but could not find anything obvious that is going
wrong.
Lukas
On 11/07/12 04:21, Wei Cao wrote:
</pre>
<blockquote type="cite">
<pre wrap="">
I added a macro to conditional compile the patch because I think it
can be more selectable, I can remove the macro, fix the compilation
error and test on mingw platform in later version.
how about provide another BIF named port_flag (like process_flag) to
let user bind port to a given scheduler?
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
<br>
<br>
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