Le mercredi 06 avril 2016 à 17:02 +0200, Johannes Wagner a écrit :
>
> >
> > On 6 Apr 2016, at 4:46 PM, Milan Bouchet-Valat <[email protected]> wrote:
> >
> > Le mercredi 06 avril 2016 à 07:25 -0700, Johannes Wagner a écrit :
> > >
> > > and last update, I disabled Hyperthreading on the i7, and now it
> > > performes as expected.
> > >
> > > i7 no HT:
> > >
> > > 1000000 loops, best of 3: 879.57 ns per loop
> > > 100000 loops, best of 3: 9.88 µs per loop
> > > 100 loops, best of 3: 4.46 ms per loop
> > > 10000 loops, best of 3: 69.89 µs per loop
> > > 10000 loops, best of 3: 26.67 µs per loop
> > > 10 loops, best of 3: 95.08 ms per loop
> > >
> > > i7 with HT:
> > >
> > > 1000000 loops, best of 3: 871.68 ns per loop
> > > 10000 loops, best of 3: 10.84 µs per loop
> > > 100 loops, best of 3: 5.19 ms per loop
> > > 10000 loops, best of 3: 71.35 µs per loop
> > > 10000 loops, best of 3: 26.65 µs per loop
> > > 1 loops, best of 3: 159.99 ms per loop
> > >
> > > So all calls inside the loop are the same speed, but the whole loop,
> > > with identical assembly code is ~60% slower if HT is enabled. Where
> > > can this problem then arise from? LLVM? or thread pinning in the OS?
> > > Probably not a julia problem then...
> > Indeed, in the last assembly output you sent, there are no differences
> > between i5 and i7 (as expected). So this isn't Julia's nor LLVM's
> > fault. No idea whether there might be an issue with the CPU itself, but
> > it's quite surprising.
> Run it on a 2nd i7 machine. Same behavior, so definitely not a faulty
> cpu. Do you have any other idea what to do? Just leave it as is and
> now use julia with disabled hyper threading is not really
> satisfactory...
Sorry, I'm clueless. You could ask on forums dedicated to CPUs or on
Intel forums. You could also try with a different OS, just in case.
Regards
> >
> > Regards
> >
> >
> > >
> > > >
> > > > Le mardi 05 avril 2016 à 10:18 -0700, Johannes Wagner a écrit :
> > > > >
> > > > > hey Milan,
> > > > > so consider following code:
> > > > >
> > > > > Pkg.clone("git://github.com/kbarbary/TimeIt.jl.git")
> > > > > using TimeIt
> > > > >
> > > > > v = rand(3)
> > > > > r = rand(6000,3)
> > > > > x = linspace(0.0, 10.0, 500) * (v./sqrt(sumabs2(v)))'
> > > > >
> > > > > dotprods = r * x[2,:]
> > > > > imexp = cis(dotprods)
> > > > > sumprod = sum(imexp) * sum(conj(imexp))
> > > > >
> > > > > f(r, x) = r * x[2,:]
> > > > > g(r, x) = r * x'
> > > > > h(imexp) = sum(imexp) * sum(conj(imexp))
> > > > >
> > > > > function s(r, x)
> > > > > result = zeros(size(x,1))
> > > > > for i = 1:size(x,1)
> > > > > imexp = cis(r * x[i,:])
> > > > > result[i]= sum(imexp) * sum(conj(imexp))
> > > > > end
> > > > > return result
> > > > > end
> > > > >
> > > > > @timeit zeros(size(x,1))
> > > > > @timeit f(r,x)
> > > > > @timeit g(r,x)
> > > > > @timeit cis(dotprods)
> > > > > @timeit h(imexp)
> > > > > @timeit s(r,x)
> > > > >
> > > > > @code_native f(r,x)
> > > > > @code_native g(r,x)
> > > > > @code_native cis(dotprods)
> > > > > @code_native h(imexp)
> > > > > @code_native s(r,x)
> > > > >
> > > > > and I attached the output of the last @code_native s(r,x) as
> > > > text
> > > > >
> > > > > files for the binary tarball, as well as the latest nalimilan
> > > > update.
> > > > >
> > > > > For the whole function s, the exported code looks actually the
> > > > same
> > > > >
> > > > > everywhere.
> > > > > But s(r,x) is the one that is considerable slower on the i7 than
> > > > the
> > > > >
> > > > > i5, whereas all the other timed calls are more or less same speed
> > > > on
> > > > >
> > > > > i5 and i7. Here are the timings in the same order as above (all
> > > > run
> > > > >
> > > > > repeatedly to not have compile time in it for last one):
> > > > >
> > > > > i7:
> > > > > 1000000 loops, best of 3: 871.68 ns per loop
> > > > > 10000 loops, best of 3: 10.84 µs per loop
> > > > > 100 loops, best of 3: 5.19 ms per loop
> > > > > 10000 loops, best of 3: 71.35 µs per loop
> > > > > 10000 loops, best of 3: 26.65 µs per loop
> > > > > 1 loops, best of 3: 159.99 ms per loop
> > > > >
> > > > > i5:
> > > > > 100000 loops, best of 3: 1.01 µs per loop
> > > > > 10000 loops, best of 3: 10.93 µs per loop
> > > > > 100 loops, best of 3: 5.09 ms per loop
> > > > > 10000 loops, best of 3: 75.93 µs per loop
> > > > > 10000 loops, best of 3: 29.23 µs per loop
> > > > > 1 loops, best of 3: 103.70 ms per loop
> > > > >
> > > > > So based on inside s(r,x) calls, the i7 should be faster, but
> > > > the
> > > > >
> > > > > whole s(r,x) is slower. Still clueless... And don't know how to
> > > > > further pin this down...
> > > > Thanks. I think you got mixed up with the different files, as the
> > > > versioninfo() output indicates. Anyway, there's enough info to
> > > > check
> > > > which file corresponds to which Julia version, so that's OK.
> > > > Indeed,
> > > > when comparing the tests with binary tarballs, there's a call
> > > > to jl_alloc_array_1d with the i7 (julia050_tarball-haswell-
> > > > i7.txt),
> > > > which is not present with the i5 (incorrectly
> > > > named julia050_haswell-
> > > > i7.txt). This is really unexpected.
> > > >
> > > > Could you file an issue on GitHub with a summary of what we've
> > > > found
> > > > (essentially your message), as well as links to 3 Gists giving the
> > > > code
> > > > and the contents of the two .txt files I mentioned above? That
> > > > would be
> > > > very helpful. Do not mention the Fedora packages at all, as the
> > > > binary
> > > > tarballs are closer to what Julia developers use.
> > > >
> > > >
> > > > Regards
> > > >
> > > >
> > > > >
> > > > > cheers, Johannes
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > >
> > > > > > Le lundi 04 avril 2016 à 10:36 -0700, Johannes Wagner a
> > > > écrit :
> > > > >
> > > > > >
> > > > > > >
> > > > > > > hey guys,
> > > > > > > so attached you find text files with @code_native output for
> > > > the
> > > > >
> > > > > >
> > > > > > >
> > > > > > > instructions
> > > > > > > - r * x[1,:]
> > > > > > > - cis(imexp)
> > > > > > > - sum(imexp) * sum(conj(imexp))
> > > > > > >
> > > > > > > for julia 0.5.
> > > > > > >
> > > > > > > Hardware I run on is a Haswell i5 machine, a Haswell i7
> > > > machine,
> > > > >
> > > > > >
> > > > > > and
> > > > > > >
> > > > > > > a IvyBridge i5 machine. Turned out on an Haswell i5 machine
> > > > the
> > > > >
> > > > > >
> > > > > > code
> > > > > > >
> > > > > > > also runs fast. Only the Haswell i7 machine is the slow one.
> > > > > > This
> > > > > > >
> > > > > > > really drove me nuts. First I thought it was the OS, then
> > > > the
> > > > >
> > > > > >
> > > > > > >
> > > > > > > architecture, and now its just from i5 to i7.... Anyways, I
> > > > > > don't
> > > > > > >
> > > > > > > know anything about x86 assembly, but the julia 0.45 code is
> > > > the
> > > > >
> > > > > >
> > > > > > same
> > > > > > >
> > > > > > > on all machines. However, for the dot product, the 0.5 code
> > > > has
> > > > >
> > > > > >
> > > > > > >
> > > > > > > already 2 different instructions on the i5 vs. the i7 (line
> > > > > > 44&47).
> > > > > > >
> > > > > > > For the cis call also (line 149...). And the IvyBridge i5
> > > > code
> > > > >
> > > > > >
> > > > > > is
> > > > > > >
> > > > > > > similar to the Haswell i5. I included also versioninfo() at
> > > > the
> > > > >
> > > > > >
> > > > > > top
> > > > > > >
> > > > > > > of the file. So you could just look at a vimdiff of the
> > > > julia0.5
> > > > >
> > > > > >
> > > > > > >
> > > > > > > files... Can anyone make sense out of this?
> > > > > > I'm definitely not an expert in assembly, but that additional
> > > > leaq
> > > > >
> > > > > >
> > > > > > instruction on line 44, and the additional movq instructions
> > > > on
> > > > >
> > > > > >
> > > > > > line
> > > > > > 111, 151 and 152 really look weird
> > > > > >
> > > > > > Could you do the same test with the binary tarballs? If the
> > > > > > difference
> > > > > > persists, you should open an issue on GitHub to track this.
> > > > > >
> > > > > > BTW, please wrap the fist call in a function to ensure it is
> > > > > > specialized for the arguments types, i.e.:
> > > > > >
> > > > > > f(r, x) = r * x[1,:]
> > > > > > @code_native f(r, x)
> > > > > >
> > > > > > Also, please check whether you still see the difference with
> > > > this
> > > > >
> > > > > >
> > > > > > code:
> > > > > > g(r, x) = r * x
> > > > > > @code_native g(r, x[1,:])
> > > > > >
> > > > > > What are the types of r and x? Could you provide a simple
> > > > > > reproducible example with dummy values?
> > > > > >
> > > > > > >
> > > > > > > The binary tarballs I will still test. If I remove the cis()
> > > > > > call,
> > > > > > >
> > > > > > > the difference is hard to tell, the loop is ~10times faster
> > > > and
> > > > >
> > > > > >
> > > > > > more
> > > > > > >
> > > > > > > or less all around 5ms. For the whole loop with cis() call,
> > > > from
> > > > >
> > > > > >
> > > > > > i5
> > > > > > >
> > > > > > > to i7 the difference is ~ 50ms on i5 to 90ms on i7.
> > > > > > >
> > > > > > > Shall I also post the julia 0.4 code?
> > > > > > If it's identical for all machines, I don't think it's
> > > > needed.
> > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > Regards
> > > > > >
> > > > > >
> > > > > > >
> > > > > > > cheers, Johannes
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > Le mercredi 30 mars 2016 à 15:16 -0700, Johannes Wagner a
> > > > > > écrit :
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > Le mercredi 30 mars 2016 à 04:43 -0700, Johannes Wagner
> > > > a
> > > > >
> > > > > >
> > > > > > écrit :
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Sorry for not having expressed myself clearly, I
> > > > meant
> > > > >
> > > > > >
> > > > > > the latest
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > version of fedora to work fine (24 development). I
> > > > always
> > > > >
> > > > > >
> > > > > > used the
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > latest julia nightly available on the copr nalimilan
> > > > > > repo. Right now
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > that is: 0.5.0-dev+3292, Commit 9d527c5*, all use
> > > > > > > > > > > LLVM: libLLVM-3.7.1 (ORCJIT, haswell)
> > > > > > > > > > >
> > > > > > > > > > > peakflops on all machines (hardware identical) is
> > > > > > ~1.2..1.5e11.
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Fedora 22&23 with julia 0.5 is ~50% slower then 0.4,
> > > > only
> > > > >
> > > > > >
> > > > > > on fedora
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > 24 julia 0.5 is faster compared to julia 0.4.
> > > > > > > > > > Could you try to find a simple code to reproduce the
> > > > > > problem? In
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > particular, it would be useful to check whether this
> > > > comes
> > > > >
> > > > > >
> > > > > > from
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > OpenBLAS differences or whether it also happens with
> > > > pure
> > > > >
> > > > > >
> > > > > > Julia code
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > (typical operations which depend on BLAS are matrix
> > > > > > multiplication, as
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > well as most of linear algebra). Normally, 0.4 and 0.5
> > > > > > should use the
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > same BLAS, but who knows...
> > > > > > > > > well thats what I did, and the 3 simple calls inside the
> > > > loop
> > > > >
> > > > > >
> > > > > > are
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > more or less same speed. only the whole loop seems
> > > > slower.
> > > > >
> > > > > >
> > > > > > See my
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > code sample fromanswer march 8th (code gets in same
> > > > > > proportions
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > faster when exp(im .* dotprods) is replaced by
> > > > cis(dotprods)
> > > > >
> > > > > >
> > > > > > ).
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > So I don't know what I can do then...
> > > > > > > > Sorry, somehow I had missed that message. This indeed
> > > > looks
> > > > >
> > > > > >
> > > > > > like a code
> > > > > > >
> > > > > > > >
> > > > > > > > generation issue in Julia/LLVM.
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > Can you also confirm that all versioninfo() fields are
> > > > the
> > > > >
> > > > > >
> > > > > > same for all
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > three machines, both for 0.4 and 0.5? We must envision
> > > > the
> > > > >
> > > > > >
> > > > > > possibility
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > that the differences actually come from 0.4.
> > > > > > > > > ohoh, right! just noticed that my fedora 24 machine was
> > > > an
> > > > >
> > > > > >
> > > > > > ivy bridge
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > which works fast:
> > > > > > > > >
> > > > > > > > > Julia Version 0.5.0-dev+3292
> > > > > > > > > Commit 9d527c5* (2016-03-28 06:55 UTC)
> > > > > > > > > Platform Info:
> > > > > > > > > System: Linux (x86_64-redhat-linux)
> > > > > > > > > CPU: Intel(R) Core(TM) i5-3550 CPU @ 3.30GHz
> > > > > > > > > WORD_SIZE: 64
> > > > > > > > > BLAS: libopenblas (DYNAMIC_ARCH NO_AFFINITY
> > > > Sandybridge)
> > > > >
> > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > LAPACK: libopenblasp.so.0
> > > > > > > > > LIBM: libopenlibm
> > > > > > > > > LLVM: libLLVM-3.7.1 (ORCJIT, ivybridge)
> > > > > > > > >
> > > > > > > > > and the other ones with fed22/23 are haswell, which work
> > > > > > slow:
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Julia Version 0.5.0-dev+3292
> > > > > > > > > Commit 9d527c5* (2016-03-28 06:55 UTC)
> > > > > > > > > Platform Info:
> > > > > > > > > System: Linux (x86_64-redhat-linux)
> > > > > > > > > CPU: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
> > > > > > > > > WORD_SIZE: 64
> > > > > > > > > BLAS: libopenblas (DYNAMIC_ARCH NO_AFFINITY Haswell)
> > > > > > > > > LAPACK: libopenblasp.so.0
> > > > > > > > > LIBM: libopenlibm
> > > > > > > > > LLVM: libLLVM-3.7.1 (ORCJIT, haswell)
> > > > > > > > >
> > > > > > > > > I just booted an fedora 23 on the ivy bridge machine and
> > > > it's
> > > > >
> > > > > >
> > > > > > also fast.
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Now if I use julia 0.45 on both architectures:
> > > > > > > > >
> > > > > > > > > Julia Version 0.4.5
> > > > > > > > > Commit 2ac304d* (2016-03-18 00:58 UTC)
> > > > > > > > > Platform Info:
> > > > > > > > > System: Linux (x86_64-redhat-linux)
> > > > > > > > > CPU: Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
> > > > > > > > > WORD_SIZE: 64
> > > > > > > > > BLAS: libopenblas (DYNAMIC_ARCH NO_AFFINITY Haswell)
> > > > > > > > > LAPACK: libopenblasp.so.0
> > > > > > > > > LIBM: libopenlibm
> > > > > > > > > LLVM: libLLVM-3.3
> > > > > > > > >
> > > > > > > > > and:
> > > > > > > > >
> > > > > > > > > Julia Version 0.4.5
> > > > > > > > > Commit 2ac304d* (2016-03-18 00:58 UTC)
> > > > > > > > > Platform Info:
> > > > > > > > > System: Linux (x86_64-redhat-linux)
> > > > > > > > > CPU: Intel(R) Core(TM) i5-3550 CPU @ 3.30GHz
> > > > > > > > > WORD_SIZE: 64
> > > > > > > > > BLAS: libopenblas (DYNAMIC_ARCH NO_AFFINITY
> > > > Sandybridge)
> > > > >
> > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > LAPACK: libopenblasp.so.0
> > > > > > > > > LIBM: libopenlibm
> > > > > > > > > LLVM: libLLVM-3.3
> > > > > > > > >
> > > > > > > > > there is no speed difference apart from the ~10% or so
> > > > from
> > > > >
> > > > > >
> > > > > > the
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > faster haswell machine. So could perhaps be haswell
> > > > hardware
> > > > >
> > > > > >
> > > > > > target
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > specific with the change from llvm 3.3 to 3.7.1? Is
> > > > there
> > > > >
> > > > > >
> > > > > > anything
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > else I could provide?
> > > > > > > > This is certainly an interesting finding. Could you paste
> > > > > > somewhere the
> > > > > > >
> > > > > > > >
> > > > > > > > output of @code_native for your function on Sandybridge
> > > > vs.
> > > > >
> > > > > >
> > > > > > Haswell,
> > > > > > >
> > > > > > > >
> > > > > > > > for both 0.4 and 0.5?
> > > > > > > >
> > > > > > > > It would also be useful to check whether the same
> > > > difference
> > > > >
> > > > > >
> > > > > > appears if
> > > > > > >
> > > > > > > >
> > > > > > > > you use the generic binary tarballs from http://julialang.o
> > > > rg/d
> > > > >
> > > > > >
> > > > > > ownloads
> > > > > > >
> > > > > > > >
> > > > > > > > .
> > > > > > > >
> > > > > > > > Finally, do you get the same result if you remove the call
> > > > to
> > > > >
> > > > > >
> > > > > > exp()
> > > > > > >
> > > > > > > >
> > > > > > > > from the loop? (This is the only external function, so it
> > > > > > shouldn't be
> > > > > > >
> > > > > > > >
> > > > > > > > affected by changes in Julia.)
> > > > > > > >
> > > > > > > >
> > > > > > > > Regards
> > > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > Best, Johannes
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > Regards
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Le mercredi 16 mars 2016 à 09:25 -0700, Johannes
> > > > Wagner a
> > > > >
> > > > > >
> > > > > > écrit :
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > just a little update. Tested some other fedoras:
> > > > Fedora
> > > > >
> > > > > >
> > > > > > 22 with llvm
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > 3.8 is also slow with julia 0.5, whereas a fedora
> > > > 24
> > > > >
> > > > > >
> > > > > > branch with llvm
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > 3.7 is faster on julia 0.5 compared to julia 0.4,
> > > > as it
> > > > >
> > > > > >
> > > > > > should be
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > (speedup from inner loop parts translated into
> > > > speedup
> > > > >
> > > > > >
> > > > > > to whole
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > function).
> > > > > > > > > > > >
> > > > > > > > > > > > don't know if anyone cares about that... At least
> > > > the
> > > > >
> > > > > >
> > > > > > latest version
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > seems to work fine, hope it stays like this into
> > > > the
> > > > >
> > > > > >
> > > > > > final fedora 24
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > What's the "latest version"? git built from source or
> > > > RPM
> > > > >
> > > > > >
> > > > > > nightlies?
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > With which LLVM version for each?
> > > > > > > > > > >
> > > > > > > > > > > If from the RPMs, I've switched them to LLVM 3.8 for
> > > > a
> > > > >
> > > > > >
> > > > > > few days, and
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > went back to 3.7 because of a build failure. So that
> > > > > > might explain the
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > difference. You can install the last version which
> > > > built
> > > > >
> > > > > >
> > > > > > with LLVM 3.8
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > manually from here:
> > > > > > > > > > > https://copr-be.cloud.fedoraproject.org/results/nalim
> > > > ilan
> > > > >
> > > > > >
> > > > > > /julia-nightlies/fedora-23-x86_64/00167549-julia/
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > It would be interesting to compare it with the
> > > > latest
> > > > >
> > > > > >
> > > > > > nightly with 3.7.
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Regards
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > hey guys,
> > > > > > > > > > > > > I just experienced something weird. I have some
> > > > code
> > > > >
> > > > > >
> > > > > > that runs fine
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > on 0.43, then I updated to 0.5dev to test the
> > > > new
> > > > >
> > > > > >
> > > > > > Arrays, run same
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > code and noticed it got about ~50% slower. Then
> > > > I
> > > > >
> > > > > >
> > > > > > downgraded back
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > to 0.43, ran the old code, but speed remained
> > > > slow. I
> > > > >
> > > > > >
> > > > > > noticed while
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > reinstalling 0.43, openblas-threads didn't get
> > > > > > isntalled along with
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > it. So I manually installed it, but no
> > > > change.
> > > > >
> > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > Does anyone has an idea what could be going on?
> > > > LLVM
> > > > >
> > > > > >
> > > > > > on fedora23 is
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > 3.7
> > > > > > > > > > > > >
> > > > > > > > > > > > > Cheers, Johannes
> > > > > > > > > > > > >
