From: Erwan Velu <e.velu@criteo.com>
Date: Thu, 16 Sep 2021 16:46:30 +0000 (+0200)
Subject: t/io_uring: Reporting bandwidth
X-Git-Tag: fio-3.29~99^2
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=22fd35012cea;p=fio.git

t/io_uring: Reporting bandwidth

When performing tests at various block size, it's sometimes a bit
difficult to estimate if we reach the limit of the datapath.

This commit offer to simply prints the resulting bandwitdh of the IOPS
multiplied by the block size.

A typical output looks like :

  [user@hosŧ] t/io_uring -b512 -d128 -c32 -s32 -p1 -F1 -B1 -n4 /dev/nvme0n1
   ...
   IOPS=729856, BW=356 MiB/s, IOS/call=32/32, inflight=(105 119 108 109)

  [user@host] t/io_uring -b4096 -d128 -c32 -s32 -p1 -F1 -B1 -n4 /dev/nvme0n1
   ...
   IOPS=746368, BW=2915 MiB/s, IOS/call=32/31, inflight=(121 115 122 122)

In the 4K case, as for a PCI Gen3 product, we are clearly limited by the
bandwidth while in the 512 case we hit latency issues.

BW is expressed in MiB/sec.

Signed-off-by: Erwan Velu <e.velu@criteo.com>
---

diff --git a/t/io_uring.c b/t/io_uring.c
index 0acbf0b4..cf59fe37 100644
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -727,6 +727,7 @@ int main(int argc, char *argv[])
 		unsigned long this_reap = 0;
 		unsigned long this_call = 0;
 		unsigned long rpc = 0, ipc = 0;
+		unsigned long iops;
 
 		sleep(1);
 		for (j = 0; j < nthreads; j++) {
@@ -740,8 +741,9 @@ int main(int argc, char *argv[])
 		} else
 			rpc = ipc = -1;
 		file_depths(fdepths);
-		printf("IOPS=%lu, IOS/call=%ld/%ld, inflight=(%s)\n",
-				this_done - done, rpc, ipc, fdepths);
+		iops = this_done - done;
+		printf("IOPS=%lu, BW=%luMiB/s, IOS/call=%ld/%ld, inflight=(%s)\n",
+				iops, iops * (1048576 / bs), rpc, ipc, fdepths);
 		done = this_done;
 		calls = this_call;
 		reap = this_reap;