linux-kernel - Re: [BUG] - Short freezes in gameplay due to MMC_CAP_AGGRESSIVE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <2d3b720c-5637-45e7-887d-077b1e9b3c23@acm.org>
Date: Tue, 3 Feb 2026 10:10:55 -0800
From: Bart Van Assche <bvanassche@....org>
To: Ulf Hansson <ulf.hansson@...aro.org>
Cc: Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...nel.dk>,
 Ricky WU <ricky_wu@...ltek.com>,
 Matthew Schwartz <matthew.schwartz@...ux.dev>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "linux-mmc@...r.kernel.org" <linux-mmc@...r.kernel.org>,
 linux-block <linux-block@...r.kernel.org>
Subject: Re: [BUG] - Short freezes in gameplay due to MMC_CAP_AGGRESSIVE_PM on
 RTS525A card reader

On 2/3/26 3:28 AM, Ulf Hansson wrote:
> I guess the question then is, do we always want zero latency, which I
> assume must be costly from a power savings point of view. At least
> during the idle period, while not serving I/O and waiting for the
> device to be runtime suspended.

Block I/O latency suffers if a CPU core enters a lower power state while
waiting for an I/O completion. Hence the choice in the UFS driver for
not allowing CPU cores to enter a lower power state while any block I/O
is in progress.

Bart.