[v4] tools/xenstore: rework internal accounting

[PATCH v4 10/13] tools/xenstore: switch transaction accounting to generic accounting

Posted by Juergen Gross 2 years, 10 months ago

As transaction accounting is active for unprivileged domains only, it
can easily be added to the generic per-domain accounting.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 tools/xenstore/xenstored_core.c        |  3 +--
 tools/xenstore/xenstored_core.h        |  1 -
 tools/xenstore/xenstored_domain.c      | 21 ++++++++++++++++++---
 tools/xenstore/xenstored_domain.h      |  4 ++++
 tools/xenstore/xenstored_transaction.c | 12 +++++-------
 5 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
index 2d481fcad9..88c569b7d5 100644
--- a/tools/xenstore/xenstored_core.c
+++ b/tools/xenstore/xenstored_core.c
@@ -2083,7 +2083,7 @@ static void consider_message(struct connection *conn)
 	 * stalled. This will ignore new requests until Live-Update happened
 	 * or it was aborted.
 	 */
-	if (lu_is_pending() && conn->transaction_started == 0 &&
+	if (lu_is_pending() && conn->ta_start_time == 0 &&
 	    conn->in->hdr.msg.type == XS_TRANSACTION_START) {
 		trace("Delaying transaction start for connection %p req_id %u\n",
 		      conn, conn->in->hdr.msg.req_id);
@@ -2190,7 +2190,6 @@ struct connection *new_connection(const struct interface_funcs *funcs)
 	new->funcs = funcs;
 	new->is_ignored = false;
 	new->is_stalled = false;
-	new->transaction_started = 0;
 	INIT_LIST_HEAD(&new->out_list);
 	INIT_LIST_HEAD(&new->acc_list);
 	INIT_LIST_HEAD(&new->ref_list);
diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
index 5a11dc1231..3564d85d7d 100644
--- a/tools/xenstore/xenstored_core.h
+++ b/tools/xenstore/xenstored_core.h
@@ -151,7 +151,6 @@ struct connection
 	/* List of in-progress transactions. */
 	struct list_head transaction_list;
 	uint32_t next_transaction_id;
-	unsigned int transaction_started;
 	time_t ta_start_time;
 
 	/* List of delayed requests. */
diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
index 1caa60bb14..40bcc1dbfa 100644
--- a/tools/xenstore/xenstored_domain.c
+++ b/tools/xenstore/xenstored_domain.c
@@ -419,12 +419,10 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 {
 	struct domain *d = find_domain_struct(domid);
 	char *resp;
-	int ta;
 
 	if (!d)
 		return ENOENT;
 
-	ta = d->conn ? d->conn->transaction_started : 0;
 	resp = talloc_asprintf(ctx, "Domain %u:\n", domid);
 	if (!resp)
 		return ENOMEM;
@@ -435,7 +433,7 @@ int domain_get_quota(const void *ctx, struct connection *conn,
 
 	ent(nodes, d->acc[ACC_NODES]);
 	ent(watches, d->acc[ACC_WATCH]);
-	ent(transactions, ta);
+	ent(transactions, d->acc[ACC_TRANS]);
 	ent(outstanding, d->acc[ACC_OUTST]);
 	ent(memory, d->acc[ACC_MEM]);
 
@@ -1297,6 +1295,23 @@ void domain_outstanding_dec(struct connection *conn, unsigned int domid)
 	domain_acc_add(conn, domid, ACC_OUTST, -1, true);
 }
 
+void domain_transaction_inc(struct connection *conn)
+{
+	domain_acc_add(conn, conn->id, ACC_TRANS, 1, true);
+}
+
+void domain_transaction_dec(struct connection *conn)
+{
+	domain_acc_add(conn, conn->id, ACC_TRANS, -1, true);
+}
+
+unsigned int domain_transaction_get(struct connection *conn)
+{
+	return (domain_is_unprivileged(conn))
+		? domain_acc_add(conn, conn->id, ACC_TRANS, 0, true)
+		: 0;
+}
+
 static wrl_creditt wrl_config_writecost      = WRL_FACTOR;
 static wrl_creditt wrl_config_rate           = WRL_RATE   * WRL_FACTOR;
 static wrl_creditt wrl_config_dburst         = WRL_DBURST * WRL_FACTOR;
diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
index 0d61bf4344..abc766f343 100644
--- a/tools/xenstore/xenstored_domain.h
+++ b/tools/xenstore/xenstored_domain.h
@@ -31,6 +31,7 @@ enum accitem {
 	ACC_WATCH = ACC_TR_N,
 	ACC_OUTST,
 	ACC_MEM,
+	ACC_TRANS,
 	ACC_N,			/* Number of elements per domain. */
 };
 
@@ -112,6 +113,9 @@ void domain_watch_dec(struct connection *conn);
 int domain_watch(struct connection *conn);
 void domain_outstanding_inc(struct connection *conn, unsigned int domid);
 void domain_outstanding_dec(struct connection *conn, unsigned int domid);
+void domain_transaction_inc(struct connection *conn);
+void domain_transaction_dec(struct connection *conn);
+unsigned int domain_transaction_get(struct connection *conn);
 int domain_get_quota(const void *ctx, struct connection *conn,
 		     unsigned int domid);
 
diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c
index 11c8bcec84..1c14b8579a 100644
--- a/tools/xenstore/xenstored_transaction.c
+++ b/tools/xenstore/xenstored_transaction.c
@@ -479,8 +479,7 @@ int do_transaction_start(const void *ctx, struct connection *conn,
 	if (conn->transaction)
 		return EBUSY;
 
-	if (domain_is_unprivileged(conn) &&
-	    conn->transaction_started > quota_max_transaction)
+	if (domain_transaction_get(conn) > quota_max_transaction)
 		return ENOSPC;
 
 	/* Attach transaction to ctx for autofree until it's complete */
@@ -505,9 +504,9 @@ int do_transaction_start(const void *ctx, struct connection *conn,
 	list_add_tail(&trans->list, &conn->transaction_list);
 	talloc_steal(conn, trans);
 	talloc_set_destructor(trans, destroy_transaction);
-	if (!conn->transaction_started)
+	if (!conn->ta_start_time)
 		conn->ta_start_time = time(NULL);
-	conn->transaction_started++;
+	domain_transaction_inc(conn);
 	wrl_ntransactions++;
 
 	snprintf(id_str, sizeof(id_str), "%u", trans->id);
@@ -533,8 +532,8 @@ int do_transaction_end(const void *ctx, struct connection *conn,
 
 	conn->transaction = NULL;
 	list_del(&trans->list);
-	conn->transaction_started--;
-	if (!conn->transaction_started)
+	domain_transaction_dec(conn);
+	if (list_empty(&conn->transaction_list))
 		conn->ta_start_time = 0;
 
 	chk_quota = trans->node_created && domain_is_unprivileged(conn);
@@ -588,7 +587,6 @@ void conn_delete_all_transactions(struct connection *conn)
 
 	assert(conn->transaction == NULL);
 
-	conn->transaction_started = 0;
 	conn->ta_start_time = 0;
 }
 
-- 
2.35.3

Re: [PATCH v4 10/13] tools/xenstore: switch transaction accounting to generic accounting

Posted by Julien Grall 2 years, 9 months ago

Hi,

On 05/04/2023 08:03, Juergen Gross wrote:
> As transaction accounting is active for unprivileged domains only, it
> can easily be added to the generic per-domain accounting.
> 
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
>   tools/xenstore/xenstored_core.c        |  3 +--
>   tools/xenstore/xenstored_core.h        |  1 -
>   tools/xenstore/xenstored_domain.c      | 21 ++++++++++++++++++---
>   tools/xenstore/xenstored_domain.h      |  4 ++++
>   tools/xenstore/xenstored_transaction.c | 12 +++++-------
>   5 files changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
> index 2d481fcad9..88c569b7d5 100644
> --- a/tools/xenstore/xenstored_core.c
> +++ b/tools/xenstore/xenstored_core.c
> @@ -2083,7 +2083,7 @@ static void consider_message(struct connection *conn)
>   	 * stalled. This will ignore new requests until Live-Update happened
>   	 * or it was aborted.
>   	 */
> -	if (lu_is_pending() && conn->transaction_started == 0 &&
> +	if (lu_is_pending() && conn->ta_start_time == 0 &&

NIT: I know there are some places in the code checking for 
conn->ta_start_time == 0. But it feels like a better replacement to 
"conn->transaction_started" is "list_empty(...)".

I agree this is going to be more expensive. But you are switching the 
transaction accounting to a generic infrastructure which is pretty heavy 
compare to a simple addition/substraction. So I think a "list_empty()" 
would be OK here.

>   	    conn->in->hdr.msg.type == XS_TRANSACTION_START) {
>   		trace("Delaying transaction start for connection %p req_id %u\n",
>   		      conn, conn->in->hdr.msg.req_id);
> @@ -2190,7 +2190,6 @@ struct connection *new_connection(const struct interface_funcs *funcs)
>   	new->funcs = funcs;
>   	new->is_ignored = false;
>   	new->is_stalled = false;
> -	new->transaction_started = 0;
>   	INIT_LIST_HEAD(&new->out_list);
>   	INIT_LIST_HEAD(&new->acc_list);
>   	INIT_LIST_HEAD(&new->ref_list);
> diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
> index 5a11dc1231..3564d85d7d 100644
> --- a/tools/xenstore/xenstored_core.h
> +++ b/tools/xenstore/xenstored_core.h
> @@ -151,7 +151,6 @@ struct connection
>   	/* List of in-progress transactions. */
>   	struct list_head transaction_list;
>   	uint32_t next_transaction_id;
> -	unsigned int transaction_started;
>   	time_t ta_start_time;
>   
>   	/* List of delayed requests. */
> diff --git a/tools/xenstore/xenstored_domain.c b/tools/xenstore/xenstored_domain.c
> index 1caa60bb14..40bcc1dbfa 100644
> --- a/tools/xenstore/xenstored_domain.c
> +++ b/tools/xenstore/xenstored_domain.c
> @@ -419,12 +419,10 @@ int domain_get_quota(const void *ctx, struct connection *conn,
>   {
>   	struct domain *d = find_domain_struct(domid);
>   	char *resp;
> -	int ta;
>   
>   	if (!d)
>   		return ENOENT;
>   
> -	ta = d->conn ? d->conn->transaction_started : 0;
>   	resp = talloc_asprintf(ctx, "Domain %u:\n", domid);
>   	if (!resp)
>   		return ENOMEM;
> @@ -435,7 +433,7 @@ int domain_get_quota(const void *ctx, struct connection *conn,
>   
>   	ent(nodes, d->acc[ACC_NODES]);
>   	ent(watches, d->acc[ACC_WATCH]);
> -	ent(transactions, ta);
> +	ent(transactions, d->acc[ACC_TRANS]);
>   	ent(outstanding, d->acc[ACC_OUTST]);
>   	ent(memory, d->acc[ACC_MEM]);
>   
> @@ -1297,6 +1295,23 @@ void domain_outstanding_dec(struct connection *conn, unsigned int domid)
>   	domain_acc_add(conn, domid, ACC_OUTST, -1, true);
>   }
>   
> +void domain_transaction_inc(struct connection *conn)
> +{
> +	domain_acc_add(conn, conn->id, ACC_TRANS, 1, true);
> +}
> +
> +void domain_transaction_dec(struct connection *conn)
> +{
> +	domain_acc_add(conn, conn->id, ACC_TRANS, -1, true);
> +}
> +
> +unsigned int domain_transaction_get(struct connection *conn)
> +{
> +	return (domain_is_unprivileged(conn))
> +		? domain_acc_add(conn, conn->id, ACC_TRANS, 0, true)
> +		: 0;
> +}
> +
>   static wrl_creditt wrl_config_writecost      = WRL_FACTOR;
>   static wrl_creditt wrl_config_rate           = WRL_RATE   * WRL_FACTOR;
>   static wrl_creditt wrl_config_dburst         = WRL_DBURST * WRL_FACTOR;
> diff --git a/tools/xenstore/xenstored_domain.h b/tools/xenstore/xenstored_domain.h
> index 0d61bf4344..abc766f343 100644
> --- a/tools/xenstore/xenstored_domain.h
> +++ b/tools/xenstore/xenstored_domain.h
> @@ -31,6 +31,7 @@ enum accitem {
>   	ACC_WATCH = ACC_TR_N,
>   	ACC_OUTST,
>   	ACC_MEM,
> +	ACC_TRANS,
>   	ACC_N,			/* Number of elements per domain. */
>   };
>   
> @@ -112,6 +113,9 @@ void domain_watch_dec(struct connection *conn);
>   int domain_watch(struct connection *conn);
>   void domain_outstanding_inc(struct connection *conn, unsigned int domid);
>   void domain_outstanding_dec(struct connection *conn, unsigned int domid);
> +void domain_transaction_inc(struct connection *conn);
> +void domain_transaction_dec(struct connection *conn);
> +unsigned int domain_transaction_get(struct connection *conn);
>   int domain_get_quota(const void *ctx, struct connection *conn,
>   		     unsigned int domid);
>   
> diff --git a/tools/xenstore/xenstored_transaction.c b/tools/xenstore/xenstored_transaction.c
> index 11c8bcec84..1c14b8579a 100644
> --- a/tools/xenstore/xenstored_transaction.c
> +++ b/tools/xenstore/xenstored_transaction.c
> @@ -479,8 +479,7 @@ int do_transaction_start(const void *ctx, struct connection *conn,
>   	if (conn->transaction)
>   		return EBUSY;
>   
> -	if (domain_is_unprivileged(conn) &&
> -	    conn->transaction_started > quota_max_transaction)
> +	if (domain_transaction_get(conn) > quota_max_transaction)
>   		return ENOSPC;
>   
>   	/* Attach transaction to ctx for autofree until it's complete */
> @@ -505,9 +504,9 @@ int do_transaction_start(const void *ctx, struct connection *conn,
>   	list_add_tail(&trans->list, &conn->transaction_list);
>   	talloc_steal(conn, trans);
>   	talloc_set_destructor(trans, destroy_transaction);
> -	if (!conn->transaction_started)
> +	if (!conn->ta_start_time)

I think it would make more sense to move this if just before the 
list_add_tail() and use (list_empty()) for the checked. This would make 
the code more consistent...

>   		conn->ta_start_time = time(NULL);
> -	conn->transaction_started++;
> +	domain_transaction_inc(conn);
>   	wrl_ntransactions++;
>   
>   	snprintf(id_str, sizeof(id_str), "%u", trans->id);
> @@ -533,8 +532,8 @@ int do_transaction_end(const void *ctx, struct connection *conn,
>   
>   	conn->transaction = NULL;
>   	list_del(&trans->list);
> -	conn->transaction_started--;
> -	if (!conn->transaction_started)
> +	domain_transaction_dec(conn);
> +	if (list_empty(&conn->transaction_list))
>   		conn->ta_start_time = 0;

... with this check and also easier to spot they are related.

>   
>   	chk_quota = trans->node_created && domain_is_unprivileged(conn);
> @@ -588,7 +587,6 @@ void conn_delete_all_transactions(struct connection *conn)
>   
>   	assert(conn->transaction == NULL);
>   
> -	conn->transaction_started = 0;
>   	conn->ta_start_time = 0;
>   }
>   

Cheers,

-- 
Julien Grall

Re: [PATCH v4 10/13] tools/xenstore: switch transaction accounting to generic accounting

Posted by Juergen Gross 2 years, 9 months ago

On 02.05.23 21:19, Julien Grall wrote:
> Hi,
> 
> On 05/04/2023 08:03, Juergen Gross wrote:
>> As transaction accounting is active for unprivileged domains only, it
>> can easily be added to the generic per-domain accounting.
>>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>> ---
>>   tools/xenstore/xenstored_core.c        |  3 +--
>>   tools/xenstore/xenstored_core.h        |  1 -
>>   tools/xenstore/xenstored_domain.c      | 21 ++++++++++++++++++---
>>   tools/xenstore/xenstored_domain.h      |  4 ++++
>>   tools/xenstore/xenstored_transaction.c | 12 +++++-------
>>   5 files changed, 28 insertions(+), 13 deletions(-)
>>
>> diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
>> index 2d481fcad9..88c569b7d5 100644
>> --- a/tools/xenstore/xenstored_core.c
>> +++ b/tools/xenstore/xenstored_core.c
>> @@ -2083,7 +2083,7 @@ static void consider_message(struct connection *conn)
>>        * stalled. This will ignore new requests until Live-Update happened
>>        * or it was aborted.
>>        */
>> -    if (lu_is_pending() && conn->transaction_started == 0 &&
>> +    if (lu_is_pending() && conn->ta_start_time == 0 &&
> 
> NIT: I know there are some places in the code checking for conn->ta_start_time 
> == 0. But it feels like a better replacement to "conn->transaction_started" is 
> "list_empty(...)".

Fine with me.

> 
> I agree this is going to be more expensive. But you are switching the 
> transaction accounting to a generic infrastructure which is pretty heavy compare 
> to a simple addition/substraction. So I think a "list_empty()" would be OK here.
> 
>>           conn->in->hdr.msg.type == XS_TRANSACTION_START) {
>>           trace("Delaying transaction start for connection %p req_id %u\n",
>>                 conn, conn->in->hdr.msg.req_id);
>> @@ -2190,7 +2190,6 @@ struct connection *new_connection(const struct 
>> interface_funcs *funcs)
>>       new->funcs = funcs;
>>       new->is_ignored = false;
>>       new->is_stalled = false;
>> -    new->transaction_started = 0;
>>       INIT_LIST_HEAD(&new->out_list);
>>       INIT_LIST_HEAD(&new->acc_list);
>>       INIT_LIST_HEAD(&new->ref_list);
>> diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h
>> index 5a11dc1231..3564d85d7d 100644
>> --- a/tools/xenstore/xenstored_core.h
>> +++ b/tools/xenstore/xenstored_core.h
>> @@ -151,7 +151,6 @@ struct connection
>>       /* List of in-progress transactions. */
>>       struct list_head transaction_list;
>>       uint32_t next_transaction_id;
>> -    unsigned int transaction_started;
>>       time_t ta_start_time;
>>       /* List of delayed requests. */
>> diff --git a/tools/xenstore/xenstored_domain.c 
>> b/tools/xenstore/xenstored_domain.c
>> index 1caa60bb14..40bcc1dbfa 100644
>> --- a/tools/xenstore/xenstored_domain.c
>> +++ b/tools/xenstore/xenstored_domain.c
>> @@ -419,12 +419,10 @@ int domain_get_quota(const void *ctx, struct connection 
>> *conn,
>>   {
>>       struct domain *d = find_domain_struct(domid);
>>       char *resp;
>> -    int ta;
>>       if (!d)
>>           return ENOENT;
>> -    ta = d->conn ? d->conn->transaction_started : 0;
>>       resp = talloc_asprintf(ctx, "Domain %u:\n", domid);
>>       if (!resp)
>>           return ENOMEM;
>> @@ -435,7 +433,7 @@ int domain_get_quota(const void *ctx, struct connection 
>> *conn,
>>       ent(nodes, d->acc[ACC_NODES]);
>>       ent(watches, d->acc[ACC_WATCH]);
>> -    ent(transactions, ta);
>> +    ent(transactions, d->acc[ACC_TRANS]);
>>       ent(outstanding, d->acc[ACC_OUTST]);
>>       ent(memory, d->acc[ACC_MEM]);
>> @@ -1297,6 +1295,23 @@ void domain_outstanding_dec(struct connection *conn, 
>> unsigned int domid)
>>       domain_acc_add(conn, domid, ACC_OUTST, -1, true);
>>   }
>> +void domain_transaction_inc(struct connection *conn)
>> +{
>> +    domain_acc_add(conn, conn->id, ACC_TRANS, 1, true);
>> +}
>> +
>> +void domain_transaction_dec(struct connection *conn)
>> +{
>> +    domain_acc_add(conn, conn->id, ACC_TRANS, -1, true);
>> +}
>> +
>> +unsigned int domain_transaction_get(struct connection *conn)
>> +{
>> +    return (domain_is_unprivileged(conn))
>> +        ? domain_acc_add(conn, conn->id, ACC_TRANS, 0, true)
>> +        : 0;
>> +}
>> +
>>   static wrl_creditt wrl_config_writecost      = WRL_FACTOR;
>>   static wrl_creditt wrl_config_rate           = WRL_RATE   * WRL_FACTOR;
>>   static wrl_creditt wrl_config_dburst         = WRL_DBURST * WRL_FACTOR;
>> diff --git a/tools/xenstore/xenstored_domain.h 
>> b/tools/xenstore/xenstored_domain.h
>> index 0d61bf4344..abc766f343 100644
>> --- a/tools/xenstore/xenstored_domain.h
>> +++ b/tools/xenstore/xenstored_domain.h
>> @@ -31,6 +31,7 @@ enum accitem {
>>       ACC_WATCH = ACC_TR_N,
>>       ACC_OUTST,
>>       ACC_MEM,
>> +    ACC_TRANS,
>>       ACC_N,            /* Number of elements per domain. */
>>   };
>> @@ -112,6 +113,9 @@ void domain_watch_dec(struct connection *conn);
>>   int domain_watch(struct connection *conn);
>>   void domain_outstanding_inc(struct connection *conn, unsigned int domid);
>>   void domain_outstanding_dec(struct connection *conn, unsigned int domid);
>> +void domain_transaction_inc(struct connection *conn);
>> +void domain_transaction_dec(struct connection *conn);
>> +unsigned int domain_transaction_get(struct connection *conn);
>>   int domain_get_quota(const void *ctx, struct connection *conn,
>>                unsigned int domid);
>> diff --git a/tools/xenstore/xenstored_transaction.c 
>> b/tools/xenstore/xenstored_transaction.c
>> index 11c8bcec84..1c14b8579a 100644
>> --- a/tools/xenstore/xenstored_transaction.c
>> +++ b/tools/xenstore/xenstored_transaction.c
>> @@ -479,8 +479,7 @@ int do_transaction_start(const void *ctx, struct 
>> connection *conn,
>>       if (conn->transaction)
>>           return EBUSY;
>> -    if (domain_is_unprivileged(conn) &&
>> -        conn->transaction_started > quota_max_transaction)
>> +    if (domain_transaction_get(conn) > quota_max_transaction)
>>           return ENOSPC;
>>       /* Attach transaction to ctx for autofree until it's complete */
>> @@ -505,9 +504,9 @@ int do_transaction_start(const void *ctx, struct 
>> connection *conn,
>>       list_add_tail(&trans->list, &conn->transaction_list);
>>       talloc_steal(conn, trans);
>>       talloc_set_destructor(trans, destroy_transaction);
>> -    if (!conn->transaction_started)
>> +    if (!conn->ta_start_time)
> 
> I think it would make more sense to move this if just before the list_add_tail() 
> and use (list_empty()) for the checked. This would make the code more consistent...

Okay.


Juergen