From 2c68f6dc6e621153a708bef6c569805762da2020 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 28 Jul 2015 13:14:32 -0600 Subject: [PATCH] block: shrink struct bio down to 2 cache lines again Commit bcf2843b3f8f added ->bi_error to cleanup the error passing for struct bio, but that ended up adding 4 bytes and a 4 byte hole to the size of struct bio. For a clean config, that bumped it from 128 bytes, to 136 bytes, on x86-64. The ->bi_flags member is currently an unsigned long, but it fits easily within an int. Change it to an unsigned int, adjust the the pool offset code, and move ->bi_error into the new hole. Then we end up with a 128 byte bio again. Change the bio flag set/clear to use cmpxchg to ensure we don't lose any flags when manipulating them. Signed-off-by: Jens Axboe --- Reading git-format-patch failed