From: Tejun Heo <tj@kernel.org>
To: Dennis Zhou <dennisszhou@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>, Josef Bacik <jbacik@fb.com>,
kernel-team@fb.com, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [PATCH v2] block: make iolatency avg_lat exponentially decay
Date: Wed, 1 Aug 2018 09:10:11 -0700 [thread overview]
Message-ID: <20180801161011.GS1206094@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <20180801154958.GP1206094@devbig004.ftw2.facebook.com>
On Wed, Aug 01, 2018 at 08:49:58AM -0700, Tejun Heo wrote:
> Hello,
>
> On Tue, Jul 31, 2018 at 05:25:59PM -0700, Dennis Zhou wrote:
> ...
> > + /*
> > + * CALC_LOAD takes in a number stored in fixed point representation.
> > + * Because we are using this for IO time in ns, the values stored
> > + * are significantly larger than the FIXED_1 denominator (2048).
> > + * Therefore, rounding errors in the calculation are negligible and
> > + * can be ignored.
> > + */
> > + exp_idx = min_t(int, BLKIOLATENCY_NR_EXP_FACTORS - 1,
> > + iolat->cur_win_nsec / BLKIOLATENCY_EXP_BUCKET_SIZE);
>
> Build bot is complaining about naked 64bit div. Should use one of the
> div64*() helpers.
>
> Looks good to me. Once Johannes's concerns are addressed, please feel
> free to add
Ooh, one nitpick. total_lat_avg is a bit of a misnomer now. Maybe
rename to lat_avg?
Thanks.
--
tejun
next prev parent reply other threads:[~2018-08-01 16:10 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-01 0:25 [PATCH v2] block: make iolatency avg_lat exponentially decay Dennis Zhou
2018-08-01 4:46 ` kbuild test robot
2018-08-01 15:49 ` Tejun Heo
2018-08-01 16:10 ` Tejun Heo [this message]
2018-08-02 6:11 ` Dennis Zhou
2018-08-01 16:02 ` Johannes Weiner
2018-08-01 16:26 ` Josef Bacik
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