public inbox for cgroups@vger.kernel.org
 help / color / mirror / Atom feed
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
To: Li Jinlin <lijinlin3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
Cc: josef-DigfWCa+lFGyeJad7bwFQA@public.gmane.org,
	axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org,
	cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	liuzhiqiang26-hv44wF8Li93QT0dZR+AlfA@public.gmane.org
Subject: Re: [PATCH v2] blk-iocost: fix shift-out-of-bounds in iocg_hick_delay()
Date: Mon, 28 Nov 2022 09:58:18 -1000	[thread overview]
Message-ID: <Y4US2vFmR4pnw08Z@slm.duckdns.org> (raw)
In-Reply-To: <20221128030413.882998-1-lijinlin3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>

On Mon, Nov 28, 2022 at 11:04:13AM +0800, Li Jinlin wrote:
>  	/* calculate the current delay in effect - 1/2 every second */
>  	tdelta = now->now - iocg->delay_at;
>  	if (iocg->delay)
> -		delay = iocg->delay >> div64_u64(tdelta, USEC_PER_SEC);
> +		delay = iocg->delay >>
> +			min_t(u64, div64_u64(tdelta, USEC_PER_SEC), 63);

I replied earlier but the right thing to do here is setting delay to 0 if
the shift is >= 64.

Thanks.

-- 
tejun

  parent reply	other threads:[~2022-11-28 19:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-28  3:04 [PATCH v2] blk-iocost: fix shift-out-of-bounds in iocg_hick_delay() Li Jinlin
     [not found] ` <20221128030413.882998-1-lijinlin3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2022-11-28 19:58   ` Tejun Heo [this message]
     [not found]     ` <Y4US2vFmR4pnw08Z-NiLfg/pYEd1N0TnZuCh8vA@public.gmane.org>
2022-11-29  1:14       ` Yu Kuai
2022-11-29  2:49         ` Li Jinlin
     [not found]           ` <2830bd58-0f53-fa54-58e5-e87225b1fdf1-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2022-11-29  2:59             ` Yu Kuai
2022-11-29  4:52               ` Li Jinlin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=Y4US2vFmR4pnw08Z@slm.duckdns.org \
    --to=tj-dgejt+ai2ygdnm+yrofe0a@public.gmane.org \
    --cc=axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org \
    --cc=cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=josef-DigfWCa+lFGyeJad7bwFQA@public.gmane.org \
    --cc=lijinlin3-hv44wF8Li93QT0dZR+AlfA@public.gmane.org \
    --cc=linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
    --cc=liuzhiqiang26-hv44wF8Li93QT0dZR+AlfA@public.gmane.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox