I also saw a huge performance drop for a pretty involved piece of code when I tried a pre-release version of 0.4 a couple of weeks ago, compared to running things on 0.3.
My plan was to wait for a feature freeze of 0.4 and then investigate and report these things, I don't have the bandwidth to track these things ongoing. Maybe that would be a good rule of thumb, to ask people to look for performance regressions with existing code once there is a feature freeze on 0.4? Also, are there ongoing performance tests? Especially tests that don't micro-benchmark, but test runtimes of relatively complex pieces of code? > -----Original Message----- > From: julia-users@googlegroups.com [mailto:julia- > us...@googlegroups.com] On Behalf Of Tim Holy > Sent: Sunday, June 14, 2015 4:36 AM > To: julia-users@googlegroups.com > Subject: Re: [julia-users] Current Performance w Trunk Compared to 0.3 > > git bisect? > > Perhaps the leading candidate is > https://github.com/JuliaLang/julia/issues/11681 > which may be fixed by > https://github.com/JuliaLang/julia/pull/11683 > > --Tim > > On Sunday, June 14, 2015 02:58:19 AM Viral Shah wrote: > > FWIW, I have seen a 25% regression from 0.3 to 0.4 on a reasonably > > complex codebase, but haven't been able to isolate the offending code. > > GC time in the 0.4 run is significantly smaller than 0.3, which means > > that if you discount GC, the difference is more like 40%. I wonder if > > this is some weird interaction with the caching in the new GC, or it > > is the quality of generated code. > > > > I didn't report it yet, since it wouldn't be useful without narrowing > > down > > - but since this thread came up, I at least thought I'd register my > > observations. > > > > -viral > > > > On Friday, June 12, 2015 at 12:21:46 PM UTC-4, Tim Holy wrote: > > > Just a reminder: if anyone still sees this kind of performance > > > regression, please do provide some more detail, as it's impossible to fix > without it. > > > It's > > > really as simple as this: > > > > > > run_my_workload() # run once to force compilation @profile > > > run_my_workload() using ProfileView > > > ProfileView.view() > > > > > > and then hover over any big (especially, red) boxes along the top row. > > > Right- > > > clicking will put details into the REPL command line---if the > > > problematic > > > line(s) are indeed in base julia, and you can copy/paste them into > > > an email or issue report. You can also paste the output of > > > Profile.print(), if more detail about the full backtrace seems > > > useful (and if that output isn't too long). > > > > > > --Tim > > > > > > On Thursday, June 11, 2015 11:09:13 AM Sebastian Good wrote: > > > > I've seen the same. Looked away for a few weeks, and my code got > > > > ~5x slower. There's a lot going on so it's hard to say without > > > > detailed testing. However this code was always very sensitive to > > > > optimization to > > > > > > be > > > > > > > able to specialize code which read data of different types. I got > > > > > > massive > > > > > > > increases in memory allocations. I'll try to narrow it down, but > > > > it > > > > > > seems > > > > > > > like perhaps something was done with optimization passes or type > > > > > > inference? > > > > > > > On Wednesday, June 10, 2015 at 9:31:59 AM UTC-4, Kevin Squire wrote: > > > > > Short answer: no, poor performance across the board is not a > > > > > known > > > > > > issue. > > > > > > > > Just curious, do you see these timing issues locally as well? > > > > > In > > > > > > other > > > > > > > > words, is it a problem with Julia, or a problem with Travis (the > > > > > continuous integration framework)? > > > > > > > > > > It might be the case that some changes in v0.4 have (possibly > > > > > inadvertantly) slowed down certain workflows compared with v0.3, > > > > > > whereas > > > > > > > > others are unchanged or even faster. > > > > > > > > > > Could you run profiling and see what parts of the code are the > > > > > > slowest, > > > > > > > > and then file issues for any slowdowns, with (preferably > > > > > minimal) examples? > > > > > > > > > > Cheers, > > > > > > > > > > Kevin > > > > > > > > > > On Wed, Jun 10, 2015 at 9:10 AM, andrew cooke <and...@acooke.org > > > > > > > > > > <javascript:>> wrote: > > > > >> Is it the current poor performance / allocation a known issue? > > > > >> > > > > >> I don't know how long this has been going on, and searching for > > > > >> "performance" in issues gives a lot of hits, but I've been > > > > > > maintaining > > > > > > > >> some > > > > >> old projects and noticed that timed tests are running > > > > >> significant;y slower with trunk than 0.3. CRC.jl was 40x > > > > >> slower - I ended up cancelling > > > > > > the > > > > > > > >> Travis build, and assumed it was a weird glitch that would be fixed. > > > > > > But > > > > > > > >> now I am seeing slowdowns with IntModN.jl too (factor more like > > > > >> 4x as slow). > > > > >> > > > > >> You can see this at > > > > >> https://travis-ci.org/andrewcooke/IntModN.jl > > > > >> (compare the timing results in the two jobs) and at > > > > >> https://travis-ci.org/andrewcooke/CRC.jl/builds/66140801 (i > > > > >> have > > > > > > been > > > > > > > >> cancelling jobs there, so the examples aren't as complete). > > > > >> > > > > >> Andrew
