Comment 28 for bug 491943

Tim Gardner (timg-tpi) wrote :

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