Messages in this thread | | | Date | Sun, 15 May 2022 13:13:28 +0200 | From | Dominik Brodowski <> | Subject | Re: [PATCH] random: move initialization functions out of hot pages |
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Am Fri, May 13, 2022 at 04:29:08PM +0200 schrieb Jason A. Donenfeld: > Much of random.c is devoted to initializing the rng and accounting for > when a sufficient amount of entropy has been added. In a perfect world, > this would all happen during init, and so we could mark these functions > as __init. But in reality, this isn't the case: sometimes the rng only > finishes initializing some seconds after system init is finished. > > For this reason, at the moment, a whole host of functions that are only > used relatively close to system init and then never again are intermixed > with functions that are used in hot code all the time. This creates more > cache misses than necessary. > > In order to pack the hot code closer together, this commit moves the > initialization functions that can't be marked as __init into > .text.unlikely by way of the __cold attribute. > > Of particular note is moving credit_init_bits() into a macro wrapper > that inlines the crng_ready() static branch check. This avoids a > function call to a nop+ret, and most notably prevents extra entropy > arithmetic from being computed in mix_interrupt_randomness().
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Thanks, Dominik
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