From 319d1687697be9d6c71da4efb1c0fee74160915c Mon Sep 17 00:00:00 2001 From: Steve Best Date: Sun, 23 Aug 2026 05:37:17 -0400 Subject: [PATCH] fs/resctrl: Add "*" shorthand to set io_alloc CBM for all domains JIRA: https://redhat.atlassian.net/browse/RHEL-174711 commit d2bf45d067c728b0fe6e8f99a7386b8291e391e3 Author: Aaron Tomlin Date: Tue Mar 24 20:11:59 2026 -0400 fs/resctrl: Add "*" shorthand to set io_alloc CBM for all domains Configuring the io_alloc_cbm interface requires an explicit domain ID for each cache domain. On systems with high core counts and numerous cache clusters, this requirement becomes cumbersome for automation and management tasks that aim to apply a uniform policy. Introduce a wildcard domain ID selector "*" for the io_alloc_cbm interface. This enables users to set the same Capacity Bitmask (CBM) across all cache domains in a single operation. Signed-off-by: Aaron Tomlin Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Reinette Chatre Reviewed-by: Babu Moger Tested-by: Babu Moger Link: https://patch.msgid.link/20260325001159.447075-3-atomlin@atomlin.com (cherry picked from commit d2bf45d067c728b0fe6e8f99a7386b8291e391e3) Assisted-by: Patchpal Signed-off-by: Steve Best --- Documentation/filesystems/resctrl.rst | 8 ++++++++ fs/resctrl/ctrlmondata.c | 21 +++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst index ab8808206f32..2c44b76d6be9 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -215,6 +215,14 @@ related to allocation: # cat /sys/fs/resctrl/info/L3/io_alloc_cbm 0=00ff;1=000f + An ID of "*" configures all domains with the provided CBM. + + Example on a system that does not require a minimum number of consecutive bits in the mask:: + + # echo "*=0" > /sys/fs/resctrl/info/L3/io_alloc_cbm + # cat /sys/fs/resctrl/info/L3/io_alloc_cbm + 0=0;1=0 + When CDP is enabled "io_alloc_cbm" associated with the CDP_DATA and CDP_CODE resources may reflect the same values. For example, values read from and written to /sys/fs/resctrl/info/L3DATA/io_alloc_cbm may be reflected by diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c index 2ef53161ce11..9a7dfc48cb2e 100644 --- a/fs/resctrl/ctrlmondata.c +++ b/fs/resctrl/ctrlmondata.c @@ -954,25 +954,34 @@ static int resctrl_io_alloc_parse_line(char *line, struct rdt_resource *r, struct resctrl_schema *s, u32 closid) { enum resctrl_conf_type peer_type; + unsigned long dom_id = ULONG_MAX; struct rdt_parse_data data; struct rdt_ctrl_domain *d; + bool update_all = false; char *dom = NULL, *id; - unsigned long dom_id; next: if (!line || line[0] == '\0') return 0; + if (update_all) { + rdt_last_cmd_puts("Configurations after global '*'\n"); + return -EINVAL; + } + dom = strsep(&line, ";"); id = strsep(&dom, "="); - if (!dom || kstrtoul(id, 10, &dom_id)) { + + if (dom && !strcmp(id, "*")) { + update_all = true; + } else if (!dom || kstrtoul(id, 10, &dom_id)) { rdt_last_cmd_puts("Missing '=' or non-numeric domain\n"); return -EINVAL; } dom = strim(dom); list_for_each_entry(d, &r->ctrl_domains, hdr.list) { - if (d->hdr.id == dom_id) { + if (update_all || d->hdr.id == dom_id) { data.buf = dom; data.mode = RDT_MODE_SHAREABLE; data.closid = closid; @@ -988,10 +997,14 @@ next: &d->staged_config[s->conf_type], sizeof(d->staged_config[0])); } - goto next; + if (!update_all) + goto next; } } + if (update_all) + goto next; + rdt_last_cmd_printf("Invalid domain %lu\n", dom_id); return -EINVAL; }