On 11/19/20 10:14 AM, Pavel Begunkov wrote: > On 19/11/2020 16:46, Jens Axboe wrote: >> On 11/19/20 8:29 AM, Pavel Begunkov wrote: >>> The first patch optimises iov_iter_npages() for the bvec case, and the >>> second helps code generation to kill unreachable code. >>> >>> Pavel Begunkov (2): >>> iov_iter: optimise iov_iter_npages for bvec >>> iov_iter: optimise iter type checking >>> >>> include/linux/uio.h | 10 +++++----- >>> lib/iov_iter.c | 10 +++++----- >>> 2 files changed, 10 insertions(+), 10 deletions(-) >> >> Nice! Tested this and confirmed both the better code generation, >> and reduction in overhead in iov_iter_npages(). > > Thanks! Did you find t-put/etc. boost with your setup?
Yeah, for this kind of test, if we shave 1% off the stack overhead, that directly yields an increase in peak IOPS. My numbers were close to yours, dropped about 1% of system overhead. -- Jens Axboe
