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  1. Couchbase Server
  2. MB-10800

Memcached eats tons of CPU when built for 32-bit x86

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Details

    • Bug
    • Resolution: Fixed
    • Major
    • 3.0
    • 3.0
    • couchbase-bucket
    • Security Level: Public
    • None
    • Untriaged
    • Unknown

    Description

      Note that I'm not able to see this problem when our software is built for amd64. But both local development build and our package (I've just tried i386 ubuntu 12.04 package) see this problem.

      Memcached eats up to 400% of cpu when idle. It's easy to reproduce. Just set up single node cluster and create default bucket.

      I'm seeing lots of time spent in kernel and perf top shows kernel functions as hottest. Looking at other entries and doing strace I see that we're doing constant futex wakeups which correspond to either pthread_

      {lock,unlock}

      or pthread_cond_

      {signal,broadcast}

      .

      Running amd64 version of our software on exact same box and exact same kernel I see no problem at all.

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            iryna iryna
            alkondratenko Aleksey Kondratenko (Inactive)
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            Dates

              Created:
              Updated:
              Resolved:

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