[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20220429173006.GD174938@bgt-140510-bm01>
Date: Fri, 29 Apr 2022 17:30:07 +0000
From: Adam Manzanares <a.manzanares@...sung.com>
To: Pankaj Raghav <p.raghav@...sung.com>
CC: "jaegeuk@...nel.org" <jaegeuk@...nel.org>,
"axboe@...nel.dk" <axboe@...nel.dk>,
"snitzer@...nel.org" <snitzer@...nel.org>,
"hch@....de" <hch@....de>, "mcgrof@...nel.org" <mcgrof@...nel.org>,
"naohiro.aota@....com" <naohiro.aota@....com>,
"sagi@...mberg.me" <sagi@...mberg.me>,
"damien.lemoal@...nsource.wdc.com" <damien.lemoal@...nsource.wdc.com>,
"dsterba@...e.com" <dsterba@...e.com>,
"johannes.thumshirn@....com" <johannes.thumshirn@....com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-btrfs@...r.kernel.org" <linux-btrfs@...r.kernel.org>,
"clm@...com" <clm@...com>,
"gost.dev@...sung.com" <gost.dev@...sung.com>,
"chao@...nel.org" <chao@...nel.org>,
"linux-f2fs-devel@...ts.sourceforge.net"
<linux-f2fs-devel@...ts.sourceforge.net>,
"josef@...icpanda.com" <josef@...icpanda.com>,
"jonathan.derrick@...ux.dev" <jonathan.derrick@...ux.dev>,
"agk@...hat.com" <agk@...hat.com>,
"kbusch@...nel.org" <kbusch@...nel.org>,
"kch@...dia.com" <kch@...dia.com>,
"linux-nvme@...ts.infradead.org" <linux-nvme@...ts.infradead.org>,
"dm-devel@...hat.com" <dm-devel@...hat.com>,
"bvanassche@....org" <bvanassche@....org>,
"jiangbo.365@...edance.com" <jiangbo.365@...edance.com>,
"linux-fsdevel@...r.kernel.org" <linux-fsdevel@...r.kernel.org>,
"matias.bjorling@....com" <matias.bjorling@....com>,
"linux-block@...r.kernel.org" <linux-block@...r.kernel.org>
Subject: Re: [PATCH 13/16] null_blk: allow non power of 2 zoned devices
On Wed, Apr 27, 2022 at 06:02:52PM +0200, Pankaj Raghav wrote:
> Convert the power of 2 based calculation with zone size to be generic in
> null_zone_no with optimization for power of 2 based zone sizes.
>
> The nr_zones calculation in null_init_zoned_dev has been replaced with a
> division without special handling for power of 2 based zone sizes as
> this function is called only during the initialization and will not
> invoked in the hot path.
>
> Performance Measurement:
>
> Device:
> zone size = 128M, blocksize=4k
>
> FIO cmd:
>
> fio --name=zbc --filename=/dev/nullb0 --direct=1 --zonemode=zbd --size=23G
> --io_size=<iosize> --ioengine=io_uring --iodepth=<iod> --rw=<mode> --bs=4k
> --loops=4
>
> The following results are an average of 4 runs on AMD Ryzen 5 5600X with
> 32GB of RAM:
>
> Sequential Write:
>
> x-----------------x---------------------------------x---------------------------------x
> | IOdepth | 8 | 16 |
> x-----------------x---------------------------------x---------------------------------x
> | | KIOPS |BW(MiB/s) | Lat(usec) | KIOPS |BW(MiB/s) | Lat(usec) |
> x-----------------x---------------------------------x---------------------------------x
> | Without patch | 578 | 2257 | 12.80 | 576 | 2248 | 25.78 |
> x-----------------x---------------------------------x---------------------------------x
> | With patch | 581 | 2268 | 12.74 | 576 | 2248 | 25.85 |
> x-----------------x---------------------------------x---------------------------------x
>
> Sequential read:
>
> x-----------------x---------------------------------x---------------------------------x
> | IOdepth | 8 | 16 |
> x-----------------x---------------------------------x---------------------------------x
> | | KIOPS |BW(MiB/s) | Lat(usec) | KIOPS |BW(MiB/s) | Lat(usec) |
> x-----------------x---------------------------------x---------------------------------x
> | Without patch | 667 | 2605 | 11.79 | 675 | 2637 | 23.49 |
> x-----------------x---------------------------------x---------------------------------x
> | With patch | 667 | 2605 | 11.79 | 675 | 2638 | 23.48 |
> x-----------------x---------------------------------x---------------------------------x
>
> Random read:
>
> x-----------------x---------------------------------x---------------------------------x
> | IOdepth | 8 | 16 |
> x-----------------x---------------------------------x---------------------------------x
> | | KIOPS |BW(MiB/s) | Lat(usec) | KIOPS |BW(MiB/s) | Lat(usec) |
> x-----------------x---------------------------------x---------------------------------x
> | Without patch | 522 | 2038 | 15.05 | 514 | 2006 | 30.87 |
> x-----------------x---------------------------------x---------------------------------x
> | With patch | 522 | 2039 | 15.04 | 523 | 2042 | 30.33 |
> x-----------------x---------------------------------x---------------------------------x
>
> Minor variations are noticed in Sequential write with io depth 8 and
> in random read with io depth 16. But overall no noticeable differences
> were noticed
>
> Reviewed-by: Luis Chamberlain <mcgrof@...nel.org>
> Signed-off-by: Pankaj Raghav <p.raghav@...sung.com>
> ---
> drivers/block/null_blk/main.c | 4 ++--
> drivers/block/null_blk/zoned.c | 14 +++++++-------
> 2 files changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index c441a4972064..82a62b543782 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -1931,8 +1931,8 @@ static int null_validate_conf(struct nullb_device *dev)
> dev->mbps = 0;
>
> if (dev->zoned &&
> - (!dev->zone_size || !is_power_of_2(dev->zone_size))) {
> - pr_err("zone_size must be power-of-two\n");
> + (!dev->zone_size)) {
> + pr_err("zone_size must not be zero\n");
> return -EINVAL;
> }
>
> diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
> index dae54dd1aeac..00c34e65ef0a 100644
> --- a/drivers/block/null_blk/zoned.c
> +++ b/drivers/block/null_blk/zoned.c
> @@ -13,7 +13,10 @@ static inline sector_t mb_to_sects(unsigned long mb)
>
> static inline unsigned int null_zone_no(struct nullb_device *dev, sector_t sect)
> {
> - return sect >> ilog2(dev->zone_size_sects);
> + if (is_power_of_2(dev->zone_size_sects))
> + return sect >> ilog2(dev->zone_size_sects);
> +
> + return div64_u64(sect, dev->zone_size_sects);
> }
>
> static inline void null_lock_zone_res(struct nullb_device *dev)
> @@ -62,10 +65,6 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
> sector_t sector = 0;
> unsigned int i;
>
> - if (!is_power_of_2(dev->zone_size)) {
> - pr_err("zone_size must be power-of-two\n");
> - return -EINVAL;
> - }
> if (dev->zone_size > dev->size) {
> pr_err("Zone size larger than device capacity\n");
> return -EINVAL;
> @@ -83,8 +82,9 @@ int null_init_zoned_dev(struct nullb_device *dev, struct request_queue *q)
> zone_capacity_sects = mb_to_sects(dev->zone_capacity);
> dev_capacity_sects = mb_to_sects(dev->size);
> dev->zone_size_sects = mb_to_sects(dev->zone_size);
> - dev->nr_zones = round_up(dev_capacity_sects, dev->zone_size_sects)
> - >> ilog2(dev->zone_size_sects);
> + dev->nr_zones =
> + div64_u64(roundup(dev_capacity_sects, dev->zone_size_sects),
> + dev->zone_size_sects);
>
> dev->zones = kvmalloc_array(dev->nr_zones, sizeof(struct nullb_zone),
> GFP_KERNEL | __GFP_ZERO);
> --
> 2.25.1
>
Looks good.
Reviewed by: Adam Manzanares <a.manzanares@...sung.com>
Powered by blists - more mailing lists