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charset="utf-8" X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20250416055250epcas5p25fa8223a1bfeea5583ad8ba88c881a05 References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sending exact nr_segs, avoids bio split check and processing in block layer, which takes around 5%[1] of overall CPU utilization. In our setup, we see overall improvement of IOPS from 7.15M to 7.65M [2] and 5% less CPU utilization. [1] 3.52% io_uring [kernel.kallsyms] [k] bio_split_rw_at 1.42% io_uring [kernel.kallsyms] [k] bio_split_rw 0.62% io_uring [kernel.kallsyms] [k] bio_submit_split [2] sudo taskset -c 0,1 ./t/io_uring -b512 -d128 -c32 -s32 -p1 -F1 -B1 -n2 -r4 /dev/nvme0n1 /dev/nvme1n1 Signed-off-by: Nitesh Shetty --- io_uring/rsrc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index b36c8825550e..6fd3a4a85a9c 100644 --- a/io_uring/rsrc.c +++ b/io_uring/rsrc.c @@ -1096,6 +1096,9 @@ static int io_import_fixed(int ddir, struct iov_iter = *iter, iter->iov_offset =3D offset & ((1UL << imu->folio_shift) - 1); } } + iter->nr_segs =3D (iter->bvec->bv_offset + iter->iov_offset + + iter->count + ((1UL << imu->folio_shift) - 1)) / + (1UL << imu->folio_shift); =20 return 0; } base-commit: 834a4a689699090a406d1662b03affa8b155d025 --=20 2.43.0