• C
    rcu/torture: Dynamically allocate SRCU output buffer to avoid overflow · d1008950
    Chen Gang 提交于
    If the rcutorture SRCU output exceeds 4096 bytes, for example, if you
    have more than about 75 CPUs, it will overflow the current statically
    allocated buffer.  This commit therefore replaces this static buffer
    with a dynamically buffer whose size is based on the number of CPUs.
    
    Benefits:
    
     - Avoids both buffer overflow and output truncation.
     - Handles an arbitrarily large number of CPUs.
     - Straightforward implementation.
    
    Shortcomings:
    
     - Some memory is wasted:
    
       1 cpu now comsumes 50 - 60 bytes, and this patch provides 200 bytes.
       Therefore, for 1K CPUs, roughly 100KB of memory will be wasted.
       However, the memory is freed immediately after printing, so this
       wastage should not be a problem in practice.
    
    Testing (Fedora16 2 CPUs, 2GB RAM x86_64):
    
     - as module, with/without "torture_type=srcu".
     - build-in not boot runnable, with/without "torture_type=srcu".
     - build-in let boot runnable, with/without "torture_type=srcu".
    Signed-off-by: NChen Gang <gang.chen@asianux.com>
    Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
    d1008950
torture.c 60.9 KB