[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Mon, 12 Dec 2022 00:53:26 -0800
From: Christoph Hellwig <hch@...radead.org>
To: Tejun Heo <tj@...nel.org>
Cc: Jens Axboe <axboe@...nel.dk>, linux-block@...r.kernel.org,
linux-kernel@...r.kernel.org, darklight2357@...oud.com,
Josef Bacik <josef@...icpanda.com>,
Linus Torvalds <torvalds@...ux-foundation.org>,
cgroups@...r.kernel.org
Subject: Re: [PATCH 2/2 block/for-6.2] blk-iolatency: Make initialization lazy
> +static int blk_iolatency_try_init(char *input)
> +{
> + static DEFINE_MUTEX(init_mutex);
> + struct block_device *bdev;
> + int ret = 0;
> +
> + bdev = blkcg_conf_open_bdev(&input);
> + if (IS_ERR(bdev))
> + return PTR_ERR(bdev);
> +retry:
> ret = blkg_conf_prep(blkcg, &blkcg_policy_iolatency, buf, &ctx);
> + if (ret == -EOPNOTSUPP) {
> + ret = blk_iolatency_try_init(buf);
It's a little sad to do two block device lookups here (even if it
obviously doesn't matter for performance). I wonder if it would
make sense to explicitly support the lazy init pattern
in blkg_conf_prep somehow.
Otherwise I'm all for the lazy init.
Powered by blists - more mailing lists