[PATCH V2 01/12] nvme-core: annotate nvme_alloc_request()

[Chaitanya Kulkarni]

On 9/1/20 10:21, Sagi Grimberg wrote:
> Chaitanya, can you check the objdump that the change actually
> resulted in a different machine code, I've seen patches of this
> sort lately where this annotation didn't change anything at all.
> 

I again took the numbers with and without this patch :-

# grep BW nvme-alloc*log
nvme-alloc-default10.fio.log:   read: IOPS=66.6k, BW=260MiB/s (273MB/s)
nvme-alloc-default1.fio.log:   read: IOPS=64.9k, BW=254MiB/s (266MB/s)
nvme-alloc-default2.fio.log:   read: IOPS=65.4k, BW=256MiB/s (268MB/s)
nvme-alloc-default3.fio.log:   read: IOPS=65.1k, BW=254MiB/s (267MB/s)
nvme-alloc-default4.fio.log:   read: IOPS=67.2k, BW=263MiB/s (275MB/s)
nvme-alloc-default5.fio.log:   read: IOPS=66.3k, BW=259MiB/s (272MB/s)
nvme-alloc-default6.fio.log:   read: IOPS=64.6k, BW=252MiB/s (264MB/s)
nvme-alloc-default7.fio.log:   read: IOPS=66.0k, BW=258MiB/s (270MB/s)
nvme-alloc-default8.fio.log:   read: IOPS=64.5k, BW=252MiB/s (264MB/s)
nvme-alloc-default9.fio.log:   read: IOPS=65.4k, BW=256MiB/s (268MB/s)
nvme-alloc-likely10.fio.log:   read: IOPS=65.5k, BW=256MiB/s (268MB/s)
nvme-alloc-likely1.fio.log:   read: IOPS=65.6k, BW=256MiB/s (269MB/s)
nvme-alloc-likely2.fio.log:   read: IOPS=65.9k, BW=257MiB/s (270MB/s)
nvme-alloc-likely3.fio.log:   read: IOPS=65.4k, BW=255MiB/s (268MB/s)
nvme-alloc-likely4.fio.log:   read: IOPS=66.2k, BW=259MiB/s (271MB/s)
nvme-alloc-likely5.fio.log:   read: IOPS=66.7k, BW=261MiB/s (273MB/s)
nvme-alloc-likely6.fio.log:   read: IOPS=66.7k, BW=261MiB/s (273MB/s)
nvme-alloc-likely7.fio.log:   read: IOPS=67.8k, BW=265MiB/s (278MB/s)
nvme-alloc-likely8.fio.log:   read: IOPS=66.5k, BW=260MiB/s (273MB/s)
nvme-alloc-likely9.fio.log:   read: IOPS=65.6k, BW=256MiB/s (269MB/s)
# ./get_fio_avg.sh

Average Bandwidth nvme-alloc-default 256.40000
Average Bandwidth nvme-alloc-likely 258.60000

Average lat util nvme-alloc-default 974.25900
Average lat util nvme-alloc-likely 965.78000