SRU Justification Impact: ureadahead can cause the kernel to allocate too much RAM for tracing on a hyper-threaded system. Symptoms vary, but can result in an unbootable machine.
Patch Description: Count the number of CPUs and divide the amount allocated of trace buffer by that number. ureadahead allocates trace buffers using 'echo 128000 > /sys/kernel/debug/tracing/buffer_size_kb". Since this is a per-CPU allocation, a multi-core system can end up allocating quite a lot of RAM. Patch: see attached ** Patch added: "Patch for ureadahead_0.100.0-4.1.3" https://bugs.edge.launchpad.net/ureadahead/+bug/491943/+attachment/1505068/+files/ureadahead.diff ** Also affects: ureadahead (Ubuntu Lucid) Importance: Undecided Status: New ** Changed in: ureadahead (Ubuntu Lucid) Importance: Undecided => High ** Changed in: ureadahead (Ubuntu Lucid) Status: New => In Progress ** Changed in: ureadahead (Ubuntu Lucid) Milestone: None => ubuntu-10.04.2 ** Changed in: ureadahead (Ubuntu Lucid) Assignee: (unassigned) => Tim Gardner (timg-tpi) -- Kernel trace buffer should be set to less unrealistic value https://bugs.launchpad.net/bugs/491943 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
