diff mbox series

[net-next,2/2] net/smc: introduce statistics for ringbufs usage of net namespace

Message ID 20240805090551.80786-3-guwen@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net/smc: introduce ringbufs usage statistics | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 29 this patch: 29
netdev/build_tools success Errors and warnings before: 9 this patch: 9
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 29 this patch: 29
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 29 this patch: 29
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 135 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-08-06--00-00 (tests: 707)

Commit Message

Wen Gu Aug. 5, 2024, 9:05 a.m. UTC
The buffer size histograms in smc_stats, namely rx/tx_rmbsize, record
the sizes of ringbufs for all connections that have ever appeared in
the net namespace. They are incremental and we cannot know the actual
ringbufs usage from these. So here introduces statistics for current
ringbufs usage of existing smc connections in the net namespace into
smc_stats, it will be incremented when new connection uses a ringbuf
and decremented when the ringbuf is unused.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 include/uapi/linux/smc.h |  2 ++
 net/smc/smc_core.c       | 22 +++++++++++++++-------
 net/smc/smc_stats.c      |  8 ++++++++
 net/smc/smc_stats.h      | 27 ++++++++++++++++++---------
 4 files changed, 43 insertions(+), 16 deletions(-)

Comments

Simon Horman Aug. 6, 2024, 10:49 a.m. UTC | #1
On Mon, Aug 05, 2024 at 05:05:51PM +0800, Wen Gu wrote:
> The buffer size histograms in smc_stats, namely rx/tx_rmbsize, record
> the sizes of ringbufs for all connections that have ever appeared in
> the net namespace. They are incremental and we cannot know the actual
> ringbufs usage from these. So here introduces statistics for current
> ringbufs usage of existing smc connections in the net namespace into
> smc_stats, it will be incremented when new connection uses a ringbuf
> and decremented when the ringbuf is unused.
> 
> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>

...

> diff --git a/net/smc/smc_stats.h b/net/smc/smc_stats.h

...

> @@ -135,38 +137,45 @@ do { \
>  } \
>  while (0)
>  
> -#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _len) \
> +#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _is_add, _len) \
>  do { \
> +	typeof(_is_add) is_a = (_is_add); \
>  	typeof(_len) _l = (_len); \
>  	typeof(_tech) t = (_tech); \
>  	int _pos; \
>  	int m = SMC_BUF_MAX - 1; \
>  	if (_l <= 0) \
>  		break; \
> -	_pos = fls((_l - 1) >> 13); \
> -	_pos = (_pos <= m) ? _pos : m; \
> -	this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
> +	if (is_a) { \
> +		_pos = fls((_l - 1) >> 13); \
> +		_pos = (_pos <= m) ? _pos : m; \
> +		this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
> +		this_cpu_add((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \

Nit:

I see that due to the construction of the caller, SMC_STAT_RMB_SIZE(),
it will not occur. But checkpatch warns of possible side effects
from reuse of _smc_stats.

As great care seems to have been taken in these macros to avoid such
problems, even if theoretical, perhaps it is worth doing so here too.

f.e. A macro-local variable could store (*(_smc_stats)).smc[t] which
     I think would both resolve the problem mentioned, and make some
     lines shorter (and maybe easier to read).

> +	} else { \
> +		this_cpu_sub((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
> +	} \
>  } \
>  while (0)
>  
>  #define SMC_STAT_RMB_SUB(_smc_stats, type, t, key) \
>  	this_cpu_inc((*(_smc_stats)).smc[t].rmb ## _ ## key.type ## _cnt)
>  
> -#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _len) \
> +#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _is_add, _len) \
>  do { \
>  	struct net *_net = sock_net(&(_smc)->sk); \
>  	struct smc_stats __percpu *_smc_stats = _net->smc.smc_stats; \
> +	typeof(_is_add) is_add = (_is_add); \
>  	typeof(_is_smcd) is_d = (_is_smcd); \
>  	typeof(_is_rx) is_r = (_is_rx); \
>  	typeof(_len) l = (_len); \
>  	if ((is_d) && (is_r)) \
> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, l); \
> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, is_add, l); \
>  	if ((is_d) && !(is_r)) \
> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, l); \
> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, is_add, l); \
>  	if (!(is_d) && (is_r)) \
> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, l); \
> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, is_add, l); \
>  	if (!(is_d) && !(is_r)) \
> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, l); \
> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, is_add, l); \
>  } \
>  while (0)
>  
> -- 
> 2.32.0.3.g01195cf9f
> 
>
Wen Gu Aug. 6, 2024, 1:07 p.m. UTC | #2
On 2024/8/6 18:49, Simon Horman wrote:
> On Mon, Aug 05, 2024 at 05:05:51PM +0800, Wen Gu wrote:
>> The buffer size histograms in smc_stats, namely rx/tx_rmbsize, record
>> the sizes of ringbufs for all connections that have ever appeared in
>> the net namespace. They are incremental and we cannot know the actual
>> ringbufs usage from these. So here introduces statistics for current
>> ringbufs usage of existing smc connections in the net namespace into
>> smc_stats, it will be incremented when new connection uses a ringbuf
>> and decremented when the ringbuf is unused.
>>
>> Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
> 
> ...
> 
>> diff --git a/net/smc/smc_stats.h b/net/smc/smc_stats.h
> 
> ...
> 
>> @@ -135,38 +137,45 @@ do { \
>>   } \
>>   while (0)
>>   
>> -#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _len) \
>> +#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _is_add, _len) \
>>   do { \
>> +	typeof(_is_add) is_a = (_is_add); \
>>   	typeof(_len) _l = (_len); \
>>   	typeof(_tech) t = (_tech); \
>>   	int _pos; \
>>   	int m = SMC_BUF_MAX - 1; \
>>   	if (_l <= 0) \
>>   		break; \
>> -	_pos = fls((_l - 1) >> 13); \
>> -	_pos = (_pos <= m) ? _pos : m; \
>> -	this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
>> +	if (is_a) { \
>> +		_pos = fls((_l - 1) >> 13); \
>> +		_pos = (_pos <= m) ? _pos : m; \
>> +		this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
>> +		this_cpu_add((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
> 
> Nit:
> 
> I see that due to the construction of the caller, SMC_STAT_RMB_SIZE(),
> it will not occur. But checkpatch warns of possible side effects
> from reuse of _smc_stats.
> 
> As great care seems to have been taken in these macros to avoid such
> problems, even if theoretical, perhaps it is worth doing so here too.
> 
> f.e. A macro-local variable could store (*(_smc_stats)).smc[t] which
>       I think would both resolve the problem mentioned, and make some
>       lines shorter (and maybe easier to read).
> 

It makes sense. I will use a macro-local variable of smc_stats. Thank you!

>> +	} else { \
>> +		this_cpu_sub((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
>> +	} \
>>   } \
>>   while (0)
>>   
>>   #define SMC_STAT_RMB_SUB(_smc_stats, type, t, key) \
>>   	this_cpu_inc((*(_smc_stats)).smc[t].rmb ## _ ## key.type ## _cnt)
>>   
>> -#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _len) \
>> +#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _is_add, _len) \
>>   do { \
>>   	struct net *_net = sock_net(&(_smc)->sk); \
>>   	struct smc_stats __percpu *_smc_stats = _net->smc.smc_stats; \
>> +	typeof(_is_add) is_add = (_is_add); \
>>   	typeof(_is_smcd) is_d = (_is_smcd); \
>>   	typeof(_is_rx) is_r = (_is_rx); \
>>   	typeof(_len) l = (_len); \
>>   	if ((is_d) && (is_r)) \
>> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, l); \
>> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, is_add, l); \
>>   	if ((is_d) && !(is_r)) \
>> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, l); \
>> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, is_add, l); \
>>   	if (!(is_d) && (is_r)) \
>> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, l); \
>> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, is_add, l); \
>>   	if (!(is_d) && !(is_r)) \
>> -		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, l); \
>> +		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, is_add, l); \
>>   } \
>>   while (0)
>>   
>> -- 
>> 2.32.0.3.g01195cf9f
>>
>>
Simon Horman Aug. 6, 2024, 3:26 p.m. UTC | #3
On Tue, Aug 06, 2024 at 09:07:40PM +0800, Wen Gu wrote:
> 
> 
> On 2024/8/6 18:49, Simon Horman wrote:
> > On Mon, Aug 05, 2024 at 05:05:51PM +0800, Wen Gu wrote:
> > > The buffer size histograms in smc_stats, namely rx/tx_rmbsize, record
> > > the sizes of ringbufs for all connections that have ever appeared in
> > > the net namespace. They are incremental and we cannot know the actual
> > > ringbufs usage from these. So here introduces statistics for current
> > > ringbufs usage of existing smc connections in the net namespace into
> > > smc_stats, it will be incremented when new connection uses a ringbuf
> > > and decremented when the ringbuf is unused.
> > > 
> > > Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
> > 
> > ...
> > 
> > > diff --git a/net/smc/smc_stats.h b/net/smc/smc_stats.h
> > 
> > ...
> > 
> > > @@ -135,38 +137,45 @@ do { \
> > >   } \
> > >   while (0)
> > > -#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _len) \
> > > +#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _is_add, _len) \
> > >   do { \
> > > +	typeof(_is_add) is_a = (_is_add); \
> > >   	typeof(_len) _l = (_len); \
> > >   	typeof(_tech) t = (_tech); \
> > >   	int _pos; \
> > >   	int m = SMC_BUF_MAX - 1; \
> > >   	if (_l <= 0) \
> > >   		break; \
> > > -	_pos = fls((_l - 1) >> 13); \
> > > -	_pos = (_pos <= m) ? _pos : m; \
> > > -	this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
> > > +	if (is_a) { \
> > > +		_pos = fls((_l - 1) >> 13); \
> > > +		_pos = (_pos <= m) ? _pos : m; \
> > > +		this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
> > > +		this_cpu_add((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
> > 
> > Nit:
> > 
> > I see that due to the construction of the caller, SMC_STAT_RMB_SIZE(),
> > it will not occur. But checkpatch warns of possible side effects
> > from reuse of _smc_stats.
> > 
> > As great care seems to have been taken in these macros to avoid such
> > problems, even if theoretical, perhaps it is worth doing so here too.
> > 
> > f.e. A macro-local variable could store (*(_smc_stats)).smc[t] which
> >       I think would both resolve the problem mentioned, and make some
> >       lines shorter (and maybe easier to read).
> > 
> 
> It makes sense. I will use a macro-local variable of smc_stats. Thank you!

Great, thanks.
diff mbox series

Patch

diff --git a/include/uapi/linux/smc.h b/include/uapi/linux/smc.h
index d27b8dc50f90..304e202c03bb 100644
--- a/include/uapi/linux/smc.h
+++ b/include/uapi/linux/smc.h
@@ -253,6 +253,8 @@  enum {
 	SMC_NLA_STATS_T_TX_BYTES,	/* u64 */
 	SMC_NLA_STATS_T_RX_CNT,		/* u64 */
 	SMC_NLA_STATS_T_TX_CNT,		/* u64 */
+	SMC_NLA_STATS_T_RX_RMB_USAGE,	/* u64 */
+	SMC_NLA_STATS_T_TX_RMB_USAGE,	/* u64 */
 	__SMC_NLA_STATS_T_MAX,
 	SMC_NLA_STATS_T_MAX = __SMC_NLA_STATS_T_MAX - 1
 };
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 73c7999fc74f..f0e08ed9b434 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1209,22 +1209,30 @@  static void smcd_buf_detach(struct smc_connection *conn)
 static void smc_buf_unuse(struct smc_connection *conn,
 			  struct smc_link_group *lgr)
 {
+	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
+	bool is_smcd = lgr->is_smcd;
+	int bufsize;
+
 	if (conn->sndbuf_desc) {
-		if (!lgr->is_smcd && conn->sndbuf_desc->is_vm) {
+		bufsize = conn->sndbuf_desc->len;
+		if (!is_smcd && conn->sndbuf_desc->is_vm) {
 			smcr_buf_unuse(conn->sndbuf_desc, false, lgr);
 		} else {
-			memzero_explicit(conn->sndbuf_desc->cpu_addr, conn->sndbuf_desc->len);
+			memzero_explicit(conn->sndbuf_desc->cpu_addr, bufsize);
 			WRITE_ONCE(conn->sndbuf_desc->used, 0);
 		}
+		SMC_STAT_RMB_SIZE(smc, is_smcd, false, false, bufsize);
 	}
 	if (conn->rmb_desc) {
-		if (!lgr->is_smcd) {
+		bufsize = conn->rmb_desc->len;
+		if (!is_smcd) {
 			smcr_buf_unuse(conn->rmb_desc, true, lgr);
 		} else {
-			memzero_explicit(conn->rmb_desc->cpu_addr,
-					 conn->rmb_desc->len + sizeof(struct smcd_cdc_msg));
+			bufsize += sizeof(struct smcd_cdc_msg);
+			memzero_explicit(conn->rmb_desc->cpu_addr, bufsize);
 			WRITE_ONCE(conn->rmb_desc->used, 0);
 		}
+		SMC_STAT_RMB_SIZE(smc, is_smcd, true, false, bufsize);
 	}
 }
 
@@ -2433,7 +2441,7 @@  static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 		buf_desc = smc_buf_get_slot(bufsize_comp, lock, buf_list);
 		if (buf_desc) {
 			buf_desc->is_dma_need_sync = 0;
-			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
+			SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
 			SMC_STAT_BUF_REUSE(smc, is_smcd, is_rmb);
 			break; /* found reusable slot */
 		}
@@ -2454,7 +2462,7 @@  static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
 		}
 
 		SMC_STAT_RMB_ALLOC(smc, is_smcd, is_rmb);
-		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, bufsize);
+		SMC_STAT_RMB_SIZE(smc, is_smcd, is_rmb, true, bufsize);
 		buf_desc->used = 1;
 		down_write(lock);
 		smc_lgr_buf_list_add(lgr, is_rmb, buf_list, buf_desc);
diff --git a/net/smc/smc_stats.c b/net/smc/smc_stats.c
index ca14c0f3a07d..3f2ebc6c06ba 100644
--- a/net/smc/smc_stats.c
+++ b/net/smc/smc_stats.c
@@ -218,6 +218,14 @@  static int smc_nl_fill_stats_tech_data(struct sk_buff *skb,
 			      smc_tech->tx_bytes,
 			      SMC_NLA_STATS_PAD))
 		goto errattr;
+	if (nla_put_u64_64bit(skb, SMC_NLA_STATS_T_RX_RMB_USAGE,
+			      smc_tech->rx_rmbuse,
+			      SMC_NLA_STATS_PAD))
+		goto errattr;
+	if (nla_put_u64_64bit(skb, SMC_NLA_STATS_T_TX_RMB_USAGE,
+			      smc_tech->tx_rmbuse,
+			      SMC_NLA_STATS_PAD))
+		goto errattr;
 	if (nla_put_u64_64bit(skb, SMC_NLA_STATS_T_RX_CNT,
 			      smc_tech->rx_cnt,
 			      SMC_NLA_STATS_PAD))
diff --git a/net/smc/smc_stats.h b/net/smc/smc_stats.h
index 9d32058db2b5..04110ed359b8 100644
--- a/net/smc/smc_stats.h
+++ b/net/smc/smc_stats.h
@@ -79,6 +79,8 @@  struct smc_stats_tech {
 	u64			tx_bytes;
 	u64			rx_cnt;
 	u64			tx_cnt;
+	u64			rx_rmbuse;
+	u64			tx_rmbuse;
 };
 
 struct smc_stats {
@@ -135,38 +137,45 @@  do { \
 } \
 while (0)
 
-#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _len) \
+#define SMC_STAT_RMB_SIZE_SUB(_smc_stats, _tech, k, _is_add, _len) \
 do { \
+	typeof(_is_add) is_a = (_is_add); \
 	typeof(_len) _l = (_len); \
 	typeof(_tech) t = (_tech); \
 	int _pos; \
 	int m = SMC_BUF_MAX - 1; \
 	if (_l <= 0) \
 		break; \
-	_pos = fls((_l - 1) >> 13); \
-	_pos = (_pos <= m) ? _pos : m; \
-	this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
+	if (is_a) { \
+		_pos = fls((_l - 1) >> 13); \
+		_pos = (_pos <= m) ? _pos : m; \
+		this_cpu_inc((*(_smc_stats)).smc[t].k ## _rmbsize.buf[_pos]); \
+		this_cpu_add((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
+	} else { \
+		this_cpu_sub((*(_smc_stats)).smc[t].k ## _rmbuse, _l); \
+	} \
 } \
 while (0)
 
 #define SMC_STAT_RMB_SUB(_smc_stats, type, t, key) \
 	this_cpu_inc((*(_smc_stats)).smc[t].rmb ## _ ## key.type ## _cnt)
 
-#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _len) \
+#define SMC_STAT_RMB_SIZE(_smc, _is_smcd, _is_rx, _is_add, _len) \
 do { \
 	struct net *_net = sock_net(&(_smc)->sk); \
 	struct smc_stats __percpu *_smc_stats = _net->smc.smc_stats; \
+	typeof(_is_add) is_add = (_is_add); \
 	typeof(_is_smcd) is_d = (_is_smcd); \
 	typeof(_is_rx) is_r = (_is_rx); \
 	typeof(_len) l = (_len); \
 	if ((is_d) && (is_r)) \
-		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, l); \
+		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, rx, is_add, l); \
 	if ((is_d) && !(is_r)) \
-		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, l); \
+		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_D, tx, is_add, l); \
 	if (!(is_d) && (is_r)) \
-		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, l); \
+		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, rx, is_add, l); \
 	if (!(is_d) && !(is_r)) \
-		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, l); \
+		SMC_STAT_RMB_SIZE_SUB(_smc_stats, SMC_TYPE_R, tx, is_add, l); \
 } \
 while (0)