• J
    random: clear fast pool, crng, and batches in cpuhp bring up · 3191dd5a
    Jason A. Donenfeld 提交于
    For the irq randomness fast pool, rather than having to use expensive
    atomics, which were visibly the most expensive thing in the entire irq
    handler, simply take care of the extreme edge case of resetting count to
    zero in the cpuhp online handler, just after workqueues have been
    reenabled. This simplifies the code a bit and lets us use vanilla
    variables rather than atomics, and performance should be improved.
    
    As well, very early on when the CPU comes up, while interrupts are still
    disabled, we clear out the per-cpu crng and its batches, so that it
    always starts with fresh randomness.
    
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Theodore Ts'o <tytso@mit.edu>
    Cc: Sultan Alsawaf <sultan@kerneltoast.com>
    Cc: Dominik Brodowski <linux@dominikbrodowski.net>
    Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
    Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
    3191dd5a
random.c 48.8 KB