Commit e1535134 authored Jan 22, 2024 by James Morse Committed by Zeng Heng Jan 22, 2024

x86/resctrl: Describe resctrl's bitmap size assumptions

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8T2RT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/log/?h=mpam/snapshot/v6.7-rc2



---------------------------

resctrl stores the bitmaps and has a closid bitmap stored in u32.

MPAM supports bitmaps and partids bigger than this.

Add some preprocessor values that make it clear why MPAM clamps
some of these values.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Zeng Heng <zengheng4@huawei.com>

parent c054efea

include/linux/resctrl.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,17 @@ int proc_resctrl_show(struct seq_file *m,
		/* max value for struct rdt_domain's mbps_val */
		#define MBA_MAX_MBPS U32_MAX

		/*
		* Resctrl uses a u32 as a closid bitmap. The maximum closid is 32.
		*/
		#define RESCTRL_MAX_CLOSID 32

		/*
		* Resctrl uses u32 to hold the user-space config. The maximum bitmap size is
		* 32.
		*/
		#define RESCTRL_MAX_CBM 32

		/**
		* struct pseudo_lock_region - pseudo-lock region information
		* @s: Resctrl schema for the resource to which this