When the io_alloc feature is enabled, a portion of the cache can be
configured for shared use between hardware and software.
Update the bit_usage representation to reflect the io_alloc configuration.
Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
---
v7: New patch split from earlier patch #5.
Added resctrl_io_alloc_closid() to return max COSID.
---
Documentation/filesystems/resctrl.rst | 20 ++++++++++-----
fs/resctrl/rdtgroup.c | 37 +++++++++++++++++++++++++--
2 files changed, 49 insertions(+), 8 deletions(-)
diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst
index c7949dd44f2f..c3c412733632 100644
--- a/Documentation/filesystems/resctrl.rst
+++ b/Documentation/filesystems/resctrl.rst
@@ -89,12 +89,20 @@ related to allocation:
must be set when writing a mask.
"shareable_bits":
- Bitmask of shareable resource with other executing
- entities (e.g. I/O). User can use this when
- setting up exclusive cache partitions. Note that
- some platforms support devices that have their
- own settings for cache use which can over-ride
- these bits.
+ Bitmask of shareable resource with other executing entities
+ (e.g. I/O). Applies to all instances of this resource. User
+ can use this when setting up exclusive cache partitions.
+ Note that some platforms support devices that have their
+ own settings for cache use which can over-ride these bits.
+
+ When "io_alloc" feature is enabled, a portion of the cache
+ can be configured for shared use between hardware and software.
+
+ "bit_usage" should be used to see which portions of each cache
+ instance is configured for hardware use via "io_alloc" feature
+ because every cache instance can have its "io_alloc" bitmask
+ configured independently.
+
"bit_usage":
Annotated capacity bitmasks showing how all
instances of the resource are used. The legend is:
diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 77d08229d855..a2eea85aecc8 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -1030,6 +1030,20 @@ static int rdt_shareable_bits_show(struct kernfs_open_file *of,
return 0;
}
+/*
+ * resctrl_io_alloc_closid() - io_alloc feature routes I/O traffic using
+ * the highest available CLOSID. Retrieve the maximum CLOSID supported by the
+ * resource. Note that if Code Data Prioritization (CDP) is enabled, the number
+ * of available CLOSIDs is reduced by half.
+ */
+static u32 resctrl_io_alloc_closid(struct rdt_resource *r)
+{
+ if (resctrl_arch_get_cdp_enabled(r->rid))
+ return resctrl_arch_get_num_closid(r) / 2 - 1;
+ else
+ return resctrl_arch_get_num_closid(r) - 1;
+}
+
/*
* rdt_bit_usage_show - Display current usage of resources
*
@@ -1063,15 +1077,17 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
cpus_read_lock();
mutex_lock(&rdtgroup_mutex);
- hw_shareable = r->cache.shareable_bits;
list_for_each_entry(dom, &r->ctrl_domains, hdr.list) {
if (sep)
seq_putc(seq, ';');
+ hw_shareable = r->cache.shareable_bits;
sw_shareable = 0;
exclusive = 0;
seq_printf(seq, "%d=", dom->hdr.id);
for (i = 0; i < closids_supported(); i++) {
- if (!closid_allocated(i))
+ if (!closid_allocated(i) ||
+ (resctrl_arch_get_io_alloc_enabled(r) &&
+ i == resctrl_io_alloc_closid(r)))
continue;
ctrl_val = resctrl_arch_get_config(r, dom, i,
s->conf_type);
@@ -1099,6 +1115,23 @@ static int rdt_bit_usage_show(struct kernfs_open_file *of,
break;
}
}
+
+ /*
+ * When the "io_alloc" feature is enabled, a portion of the
+ * cache is configured for shared use between hardware and software.
+ */
+ if (resctrl_arch_get_io_alloc_enabled(r)) {
+ if (resctrl_arch_get_cdp_enabled(r->rid))
+ ctrl_val = resctrl_arch_get_config(r, dom,
+ resctrl_io_alloc_closid(r),
+ CDP_CODE);
+ else
+ ctrl_val = resctrl_arch_get_config(r, dom,
+ resctrl_io_alloc_closid(r),
+ CDP_NONE);
+ hw_shareable |= ctrl_val;
+ }
+
for (i = r->cache.cbm_len - 1; i >= 0; i--) {
pseudo_locked = dom->plr ? dom->plr->cbm : 0;
hwb = test_bit(i, &hw_shareable);
--
2.34.1
