Add bpf_cgroup_rstat_updated() and bpf_cgroup_rstat_flush() helpers
to enable bpf programs that collect and output cgroup stats
to communicate with the rstat frameworkto add a cgroup to the rstat
updated tree or trigger an rstat flush before reading stats.
ARG_ANYTHING is used here for the struct *cgroup parameter. Would it be
better to add a task_cgroup(subsys_id) helper that returns a cgroup
pointer so that we can use a BTF argument instead?
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
---
include/uapi/linux/bpf.h | 18 ++++++++++++++++++
kernel/bpf/helpers.c | 30 ++++++++++++++++++++++++++++++
scripts/bpf_doc.py | 2 ++
tools/include/uapi/linux/bpf.h | 18 ++++++++++++++++++
4 files changed, 68 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 0f4855fa85db..fce5535579d6 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -5149,6 +5149,22 @@ union bpf_attr {
* The **hash_algo** is returned on success,
* **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if
* invalid arguments are passed.
+ *
+ * void bpf_cgroup_rstat_updated(struct cgroup *cgrp)
+ * Description
+ * Notify the rstat framework that bpf stats were updated for
+ * *cgrp* on the current cpu. Directly calls cgroup_rstat_updated
+ * with the given *cgrp* and the current cpu.
+ * Return
+ * 0
+ *
+ * void bpf_cgroup_rstat_flush(struct cgroup *cgrp)
+ * Description
+ * Collect all per-cpu stats in *cgrp*'s subtree into global
+ * counters and propagate them upwards. Directly calls
+ * cgroup_rstat_flush_irqsafe with the given *cgrp*.
+ * Return
+ * 0
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -5345,6 +5361,8 @@ union bpf_attr {
FN(copy_from_user_task), \
FN(skb_set_tstamp), \
FN(ima_file_hash), \
+ FN(cgroup_rstat_updated), \
+ FN(cgroup_rstat_flush), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 315053ef6a75..d124eed97ad7 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1374,6 +1374,32 @@ void bpf_timer_cancel_and_free(void *val)
kfree(t);
}
+BPF_CALL_1(bpf_cgroup_rstat_updated, struct cgroup *, cgrp)
+{
+ cgroup_rstat_updated(cgrp, smp_processor_id());
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_cgroup_rstat_updated_proto = {
+ .func = bpf_cgroup_rstat_updated,
+ .gpl_only = false,
+ .ret_type = RET_VOID,
+ .arg1_type = ARG_ANYTHING,
+};
+
+BPF_CALL_1(bpf_cgroup_rstat_flush, struct cgroup *, cgrp)
+{
+ cgroup_rstat_flush_irqsafe(cgrp);
+ return 0;
+}
+
+static const struct bpf_func_proto bpf_cgroup_rstat_flush_proto = {
+ .func = bpf_cgroup_rstat_flush,
+ .gpl_only = false,
+ .ret_type = RET_VOID,
+ .arg1_type = ARG_ANYTHING,
+};
+
const struct bpf_func_proto bpf_get_current_task_proto __weak;
const struct bpf_func_proto bpf_get_current_task_btf_proto __weak;
const struct bpf_func_proto bpf_probe_read_user_proto __weak;
@@ -1426,6 +1452,10 @@ bpf_base_func_proto(enum bpf_func_id func_id)
return &bpf_loop_proto;
case BPF_FUNC_strncmp:
return &bpf_strncmp_proto;
+ case BPF_FUNC_cgroup_rstat_updated:
+ return &bpf_cgroup_rstat_updated_proto;
+ case BPF_FUNC_cgroup_rstat_flush:
+ return &bpf_cgroup_rstat_flush_proto;
default:
break;
}
diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index 096625242475..9e2b08557a6f 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -633,6 +633,7 @@ class PrinterHelpers(Printer):
'struct socket',
'struct file',
'struct bpf_timer',
+ 'struct cgroup',
]
known_types = {
'...',
@@ -682,6 +683,7 @@ class PrinterHelpers(Printer):
'struct socket',
'struct file',
'struct bpf_timer',
+ 'struct cgroup',
}
mapped_types = {
'u8': '__u8',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 0f4855fa85db..fce5535579d6 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -5149,6 +5149,22 @@ union bpf_attr {
* The **hash_algo** is returned on success,
* **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if
* invalid arguments are passed.
+ *
+ * void bpf_cgroup_rstat_updated(struct cgroup *cgrp)
+ * Description
+ * Notify the rstat framework that bpf stats were updated for
+ * *cgrp* on the current cpu. Directly calls cgroup_rstat_updated
+ * with the given *cgrp* and the current cpu.
+ * Return
+ * 0
+ *
+ * void bpf_cgroup_rstat_flush(struct cgroup *cgrp)
+ * Description
+ * Collect all per-cpu stats in *cgrp*'s subtree into global
+ * counters and propagate them upwards. Directly calls
+ * cgroup_rstat_flush_irqsafe with the given *cgrp*.
+ * Return
+ * 0
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -5345,6 +5361,8 @@ union bpf_attr {
FN(copy_from_user_task), \
FN(skb_set_tstamp), \
FN(ima_file_hash), \
+ FN(cgroup_rstat_updated), \
+ FN(cgroup_rstat_flush), \
/* */
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
--
2.36.0.512.ge40c2bad7a-goog
