diff mbox series

[v2,11/13] tools/xenstore: remember global and per domain max accounting values

Message ID 20230120100028.11142-12-jgross@suse.com (mailing list archive)
State Superseded
Headers show
Series tools/xenstore: rework internal accounting | expand

Commit Message

Jürgen Groß Jan. 20, 2023, 10 a.m. UTC
Add saving the maximum values of the different accounting data seen
per domain and (for unprivileged domains) globally, and print those
values via the xenstore-control quota command. Add a sub-command for
resetting the global maximum values seen.

This should help for a decision how to set the related quotas.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 docs/misc/xenstore.txt             |   5 +-
 tools/xenstore/xenstored_control.c |  22 ++++++-
 tools/xenstore/xenstored_domain.c  | 100 +++++++++++++++++++++++------
 tools/xenstore/xenstored_domain.h  |   2 +
 4 files changed, 108 insertions(+), 21 deletions(-)
diff mbox series

Patch

diff --git a/docs/misc/xenstore.txt b/docs/misc/xenstore.txt
index 8887e7df88..44a02f6724 100644
--- a/docs/misc/xenstore.txt
+++ b/docs/misc/xenstore.txt
@@ -423,7 +423,7 @@  CONTROL			<command>|[<parameters>|]
 	print|<string>
 		print <string> to syslog (xenstore runs as daemon) or
 		to console (xenstore runs as stubdom)
-	quota|[set <name> <val>|<domid>]
+	quota|[set <name> <val>|<domid>|max [-r]]
 		without parameters: print the current quota settings
 		with "set <name> <val>": set the quota <name> to new value
 		<val> (The admin should make sure all the domain usage is
@@ -432,6 +432,9 @@  CONTROL			<command>|[<parameters>|]
 		violating the new quota setting isn't increased further)
 		with "<domid>": print quota related accounting data for
 		the domain <domid>
+		with "max [-r]": show global per-domain maximum values of all
+		unprivileged domains, optionally reset the values by adding
+		"-r"
 	quota-soft|[set <name> <val>]
 		like the "quota" command, but for soft-quota.
 	help			<supported-commands>
diff --git a/tools/xenstore/xenstored_control.c b/tools/xenstore/xenstored_control.c
index cbd62556c3..a2ba64a15c 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -306,6 +306,22 @@  static int quota_get(const void *ctx, struct connection *conn,
 	return domain_get_quota(ctx, conn, atoi(vec[0]));
 }
 
+static int quota_max(const void *ctx, struct connection *conn,
+		     char **vec, int num)
+{
+	if (num > 1)
+		return EINVAL;
+
+	if (num == 1) {
+		if (!strcmp(vec[0], "-r"))
+			domain_reset_global_acc();
+		else
+			return EINVAL;
+	}
+
+	return domain_max_global_acc(ctx, conn);
+}
+
 static int do_control_quota(const void *ctx, struct connection *conn,
 			    char **vec, int num)
 {
@@ -315,6 +331,9 @@  static int do_control_quota(const void *ctx, struct connection *conn,
 	if (!strcmp(vec[0], "set"))
 		return quota_set(ctx, conn, vec + 1, num - 1, hard_quotas);
 
+	if (!strcmp(vec[0], "max"))
+		return quota_max(ctx, conn, vec + 1, num - 1);
+
 	return quota_get(ctx, conn, vec, num);
 }
 
@@ -978,7 +997,8 @@  static struct cmd_s cmds[] = {
 	{ "memreport", do_control_memreport, "[<file>]" },
 #endif
 	{ "print", do_control_print, "<string>" },
-	{ "quota", do_control_quota, "[set <name> <val>|<domid>]" },
+	{ "quota", do_control_quota,
+		"[set <name> <val>|<domid>|max [-r]]" },
 	{ "quota-soft", do_control_quota_s, "[set <name> <val>]" },
 	{ "help", do_control_help, "" },
 };
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 4d48e7a9f4..91695b6313 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -43,6 +43,8 @@  static evtchn_port_t virq_port;
 
 xenevtchn_handle *xce_handle = NULL;
 
+static unsigned int acc_global_max[ACC_N];
+
 struct domain
 {
 	/* The id of this domain */
@@ -70,7 +72,10 @@  struct domain
 	bool introduced;
 
 	/* Accounting data for this domain. */
-	unsigned int acc[ACC_N];
+	struct acc {
+		unsigned int val;
+		unsigned int max;
+	} acc[ACC_N];
 
 	/* Memory quota data for this domain. */
 	bool soft_quota_reported;
@@ -199,9 +204,9 @@  static bool domain_can_read(struct connection *conn)
 	if (domain_is_unprivileged(conn)) {
 		if (domain->wrl_credit < 0)
 			return false;
-		if (domain->acc[ACC_OUTST] >= quota_req_outstanding)
+		if (domain->acc[ACC_OUTST].val >= quota_req_outstanding)
 			return false;
-		if (domain->acc[ACC_MEM] >= quota_memory_per_domain_hard &&
+		if (domain->acc[ACC_MEM].val >= quota_memory_per_domain_hard &&
 		    quota_memory_per_domain_hard)
 			return false;
 	}
@@ -264,7 +269,7 @@  static int domain_tree_remove_sub(const void *ctx, struct connection *conn,
 		ret = WALK_TREE_SKIP_CHILDREN;
 	}
 
-	return domain->acc[ACC_NODES] ? ret : WALK_TREE_SUCCESS_STOP;
+	return domain->acc[ACC_NODES].val ? ret : WALK_TREE_SUCCESS_STOP;
 }
 
 static void domain_tree_remove(struct domain *domain)
@@ -272,7 +277,7 @@  static void domain_tree_remove(struct domain *domain)
 	int ret;
 	struct walk_funcs walkfuncs = { .enter = domain_tree_remove_sub };
 
-	if (domain->acc[ACC_NODES]) {
+	if (domain->acc[ACC_NODES].val) {
 		ret = walk_node_tree(domain, NULL, "/", &walkfuncs, domain);
 		if (ret == WALK_TREE_ERROR_STOP)
 			syslog(LOG_ERR,
@@ -426,14 +431,41 @@  int domain_get_quota(const void *ctx, struct connection *conn,
 		return ENOMEM;
 
 #define ent(t, e) \
-	resp = talloc_asprintf_append(resp, "%-16s: %8d\n", #t, e); \
+	resp = talloc_asprintf_append(resp, "%-16s: %8u (max: %8u\n", #t, \
+				      d->acc[e].val, d->acc[e].max); \
+	if (!resp) return ENOMEM
+
+	ent(nodes, ACC_NODES);
+	ent(watches, ACC_WATCH);
+	ent(transactions, ACC_TRANS);
+	ent(outstanding, ACC_OUTST);
+	ent(memory, ACC_MEM);
+
+#undef ent
+
+	send_reply(conn, XS_CONTROL, resp, strlen(resp) + 1);
+
+	return 0;
+}
+
+int domain_max_global_acc(const void *ctx, struct connection *conn)
+{
+	char *resp;
+
+	resp = talloc_asprintf(ctx, "Max. seen accounting values:\n");
+	if (!resp)
+		return ENOMEM;
+
+#define ent(t, e) \
+	resp = talloc_asprintf_append(resp, "%-16s: %8u\n", #t,   \
+				      acc_global_max[e]);         \
 	if (!resp) return ENOMEM
 
-	ent(nodes, d->acc[ACC_NODES]);
-	ent(watches, d->acc[ACC_WATCH]);
-	ent(transactions, d->acc[ACC_TRANS]);
-	ent(outstanding, d->acc[ACC_OUTST]);
-	ent(memory, d->acc[ACC_MEM]);
+	ent(nodes, ACC_NODES);
+	ent(watches, ACC_WATCH);
+	ent(transactions, ACC_TRANS);
+	ent(outstanding, ACC_OUTST);
+	ent(memory, ACC_MEM);
 
 #undef ent
 
@@ -1051,10 +1083,12 @@  int domain_adjust_node_perms(struct node *node)
 static int domain_acc_add_chk(struct domain *d, enum accitem what, int add,
 			      unsigned int domid)
 {
+	unsigned int val;
+
 	assert(what < ARRAY_SIZE(d->acc));
 
-	if ((add < 0 && -add > d->acc[what]) ||
-	    (d->acc[what] + add) > INT_MAX) {
+	if ((add < 0 && -add > d->acc[what].val) ||
+	    (d->acc[what].val + add) > INT_MAX) {
 		/*
 		 * In a transaction when a node is being added/removed AND the
 		 * same node has been added/removed outside the transaction in
@@ -1065,7 +1099,13 @@  static int domain_acc_add_chk(struct domain *d, enum accitem what, int add,
 		return (add < 0) ? 0 : INT_MAX;
 	}
 
-	return d->acc[what] + add;
+	val = d->acc[what].val + add;
+	if (val > d->acc[what].max)
+		d->acc[what].max = val;
+	if (val > acc_global_max[what] && domid_is_unprivileged(domid))
+		acc_global_max[what] = val;
+
+	return val;
 }
 
 static int domain_acc_add(struct connection *conn, unsigned int domid,
@@ -1121,10 +1161,10 @@  static int domain_acc_add(struct connection *conn, unsigned int domid,
 	}
 
 	trace_acc("global change domid %u: what=%u %u add %d\n", domid, what,
-		  d->acc[what], add);
-	d->acc[what] = domain_acc_add_chk(d, what, add, domid);
+		  d->acc[what].val, add);
+	d->acc[what].val = domain_acc_add_chk(d, what, add, domid);
 
-	return d->acc[what];
+	return d->acc[what].val;
 }
 
 void acc_drop(struct connection *conn)
@@ -1157,6 +1197,28 @@  void acc_commit(struct connection *conn)
 	conn->in = in;
 }
 
+static int domain_reset_global_acc_sub(const void *k, void *v, void *arg)
+{
+	struct domain *d = v;
+	unsigned int i;
+
+	for (i = 0; i < ACC_N; i++)
+		d->acc[i].max = d->acc[i].val;
+
+	return 0;
+}
+
+void domain_reset_global_acc(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < ACC_N; i++)
+		acc_global_max[i] = 0;
+
+	/* Set current max values seen. */
+	hashtable_iterate(domhash, domain_reset_global_acc_sub, NULL);
+}
+
 int domain_nbentry_inc(struct connection *conn, unsigned int domid)
 {
 	return (domain_acc_add(conn, domid, ACC_NODES, 1, false) < 0)
@@ -1657,7 +1719,7 @@  static int domain_check_acc_init_sub(const void *k, void *v, void *arg)
 	 * If everything is correct incrementing the value for each node will
 	 * result in dom->nodes being 0 at the end.
 	 */
-	dom->nodes = -d->acc[ACC_NODES];
+	dom->nodes = -d->acc[ACC_NODES].val;
 
 	if (!hashtable_insert(domains, &dom->domid, dom)) {
 		talloc_free(dom);
@@ -1712,7 +1774,7 @@  static int domain_check_acc_cb(const void *k, void *v, void *arg)
 	if (!d)
 		return 0;
 
-	d->acc[ACC_NODES] += dom->nodes;
+	d->acc[ACC_NODES].val += dom->nodes;
 
 	return 0;
 }
diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index e0562b0b4d..162e7dc0d0 100644
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -116,6 +116,8 @@  int domain_get_quota(const void *ctx, struct connection *conn,
 int acc_fix_domains(struct list_head *head, bool update);
 void acc_drop(struct connection *conn);
 void acc_commit(struct connection *conn);
+int domain_max_global_acc(const void *ctx, struct connection *conn);
+void domain_reset_global_acc(void);
 
 /* Write rate limiting */