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The Blender project found some fairly remarkable discrepancies between |
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what their software actually used and what glibc's ptmalloc allocated: |
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http://www.sintel.org/development/memory-jemalloc/ |
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Results such as these led Blender and others (e.g. Chrome/Chromium, |
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Firefox, Thunderbird) to bundle private versions of jemalloc. This |
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bundling situation violates our policy against bundled libraries. The |
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maintainers could just patch their software to link to libjemalloc. |
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However, it might make more sense to evaluate jemalloc as a |
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distribution-wide replacement for glibc's ptmalloc. |
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|
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It appears that run the following commands on amd64 to see how jemalloc |
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works when used system-wide: |
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echo dev-libs/jemalloc ~amd64 >> /etc/portage/package.accept_keywords |
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emerge dev-libs/jemalloc |
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echo /usr/lib64/libjemalloc.so.1 >> /etc/ld.so.preload |
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I did this on my system, verified that jemalloc was being loaded with |
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strace and rebooted. So far, sudo is broken and anything that is 32-bit |
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will have the loader print an error about the library not being |
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preloaded. On a related note, setuid binaries will obey |
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/etc/ld.so.preload, even though they ignore LD_PRELOAD. |
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There is a chance that patching jemalloc directly into glibc would solve |
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the sudo issue, but I imagine that sudo is doing something strange, |
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which likely merits attention. For now, I am using su as a substitute |
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until I look into why sudo is broken. |
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Unless a significant issue is found in jemalloc itself, I do not see any |
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reason to continue using glibc's ptmalloc over jemalloc. As far as I |
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know, FreeBSD, NetBSD, Facebook and others are using jemalloc, so I |
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expect that no significant issues will be found. jemalloc will still |
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needs testing before we can consider it. Doing good tests is hard, so I |
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would like to crowd source ideas on the appropriate way to test a malloc |
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implementation from the list. My expectation is that people on the list |
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will collectively think of better ideas than I could on my own. |
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With that said, what do people think? |
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