From eba39236f18da7a50b6c51df5d902ee72c43e760 Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Fri, 18 Nov 2022 16:52:15 -0800 Subject: [PATCH] mm: document /sys/class/bdi//min_ratio_fine knob This documents the new /sys/class/bdi//max_ratio_fine knob. [akpm@linux-foundation.org: fix htmldocs warnings] Link: https://lkml.kernel.org/r/20221119005215.3052436-21-shr@devkernel.io Signed-off-by: Stefan Roesch Cc: Chris Mason Cc: Jens Axboe Signed-off-by: Andrew Morton --- Documentation/ABI/testing/sysfs-class-bdi | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi index e9c584db316f..0d2abd88a18c 100644 --- a/Documentation/ABI/testing/sysfs-class-bdi +++ b/Documentation/ABI/testing/sysfs-class-bdi @@ -44,6 +44,21 @@ Description: (read-write) +What: /sys/class/bdi//min_ratio_fine +Date: November 2022 +Contact: Stefan Roesch +Description: + Under normal circumstances each device is given a part of the + total write-back cache that relates to its current average + writeout speed in relation to the other devices. + + The 'min_ratio_fine' parameter allows assigning a minimum reserve + of the write-back cache to a particular device. The value is + expressed as part of 1 million. For example, this is useful for + providing a minimum QoS. + + (read-write) + What: /sys/class/bdi//max_ratio Date: January 2008 Contact: Peter Zijlstra -- 2.25.1