jemalloc!

[emberian]

No description provided.

[emberian]

r? @brson

[brson]

Woo! 🌟

[brson]

This looks really great. I'm glad it was so easy to integrate.

Before landing, I'd like to collect some performance numbers on the three major platforms so we can say something about the impact it has. I opened #6897 on this, but may not be able to do it for a few days.

Pushing to try now.

[brson]

I see the following error when I build on x86_64-linux

                                               ^~~~~~~~~~~~~~
/home/brian/dev/rust2/src/librustc/middle/kind.rs:15:0: 15:21 warning: unused import [-W unused-imports (default)]
/home/brian/dev/rust2/src/librustc/middle/kind.rs:15 use middle::pat_util;
                                                     ^~~~~~~~~~~~~~~~~~~~~
compile_and_link: x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/bin/rustc
error: linking with `cc` failed with code 1
note: cc arguments: -L/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -m64 -o x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/bin/rustc x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/bin/rustc.o -L/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -lstd-c3ca5d77d81b46c1-0.7-pre -L/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -lextra-4782a756585a81-0.7-pre -L/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -lsyntax-f25ff37b2c135ff-0.7-pre -L/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -lrustc-ba32f36fc1ec12e-0.7-pre -lrustrt -lrt -lpthread -Lrustllvm -lrustllvm -lrt -ldl -lm -lmorestack -lrustrt -Wl,-rpath,$ORIGIN/../lib -Wl,-rpath,/opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib -Wl,-rpath,/usr/local/lib/rustc/x86_64-unknown-linux-gnu/lib
note: /opt/devel/rust2/build/x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/lib/librustrt.so: undefined reference to `pthread_atfork'
collect2: error: ld returned 1 exit status

error: aborting due to previous error
make: *** [x86_64-unknown-linux-gnu/stage0/lib/rustc/x86_64-unknown-linux-gnu/bin/rustc] Error 101

[pcwalton]

Isn't tcmalloc generally supposed to be faster? I feel like we should not make any moves here until we've concretely measured performance.

[emberian]

@pcwalton see #6897

[thestinger]

@pcwalton: the problem with tcmalloc is that Google isn't including many of their Chromium improvements in the gperftools tcmalloc. The upstream jemalloc gets improvements from Facebook, Mozilla, FreeBSD, etc. and it seems to be better than the easily obtainable tcmalloc from gperftools.

We could extract tcmalloc from the Chromium source and compare to it but.... I'd rather use something that actually has stable releases, documentation and a standalone build system even if it's slightly slower.

[pcwalton]

Aha, never mind then. That's unfortunate re. tcmalloc, but I suppose it can't be helped.

[brson]

Linux build failure:

http://buildbot.rust-lang.org/builders/try-linux/builds/512

[emberian]

librustrt needs to link against jemalloc's dependencies (in this case, pthreads). I do not know how to accomplish this.

[brson]

I still want to do a little testing on mac and in multithreaded scenarios. Sorry for the delay.