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Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC v.2

PATCH In review Pavel Vasilyev 4 participants 5 messages Dec 9, 2010 – Dec 10, 2010

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Networking Network drivers Documentation Networking unix sockets
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Pavel Vasilyev

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#0 lore raw

PATCH 1/1 Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC v.2

Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC.
IMHO convenient for testing.

 Documentation/networking/ip-sysctl.txt |    4 ++++
 include/net/af_unix.h                  |    1 +
 net/unix/garbage.c                     |    5 ++---
 net/unix/sysctl_net_unix.c             |    9 +++++++++
 4 files changed, 16 insertions(+), 3 deletions(-)
Documentation/networking/ip-sysctl.txt +4 -0
index 3c5e465..11e6adf 100644
@@ -1463,6 +1463,10 @@ max_dgram_qlen - INTEGER
 
 	Default: 10
 
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	Default: 16000
 
 UNDOCUMENTED:
include/net/af_unix.h +1 -0
index 18e5c3f..ea580e4 100644
@@ -15,6 +15,7 @@ extern struct sock *unix_get_socket(struct file *filp);
 #define UNIX_HASH_SIZE	256
 
 extern unsigned int unix_tot_inflight;
+extern unsigned int sysctl_inflight_trigger_gc;
 
 struct unix_address {
 	atomic_t	refcnt;
net/unix/garbage.c +2 -3
index f89f83b..c646c6b 100644
@@ -94,7 +94,7 @@ static DEFINE_SPINLOCK(unix_gc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
 
 unsigned int unix_tot_inflight;
-
+unsigned int sysctl_inflight_trigger_gc = 16000;
 
 struct sock *unix_get_socket(struct file *filp)
 {

@@ -259,7 +259,6 @@ static void inc_inflight_move_tail(struct unix_sock *u)
 }
 
 static bool gc_in_progress = false;
-#define UNIX_INFLIGHT_TRIGGER_GC 16000
 
 void wait_for_unix_gc(void)
 {

@@ -267,7 +266,7 @@ void wait_for_unix_gc(void)
 	 * If number of inflight sockets is insane,
 	 * force a garbage collect right now.
 	 */
-	if (unix_tot_inflight > UNIX_INFLIGHT_TRIGGER_GC && !gc_in_progress)
+	if (unix_tot_inflight > sysctl_inflight_trigger_gc && !gc_in_progress)
 		unix_gc();
 	wait_event(unix_gc_wait, gc_in_progress == false);
 }
net/unix/sysctl_net_unix.c +9 -0
index 397cffe..c807235 100644
@@ -23,6 +23,13 @@ static ctl_table unix_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "inflight_trigger_gc",
+		.data		= &sysctl_inflight_trigger_gc,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

@@ -41,6 +48,8 @@ int __net_init unix_sysctl_register(struct net *net)
 		goto err_alloc;
 
 	table[0].data = &net->unx.sysctl_max_dgram_qlen;
+	table[1].data = &sysctl_inflight_trigger_gc;
+
 	net->unx.ctl = register_net_sysctl_table(net, unix_path, table);
 	if (net->unx.ctl == NULL)
 		goto err_reg;

---

Signed-off-by Pavel Vasilyev <[email protected]>
#1 lore raw

Pavel Vasilyev wrote, at 12/10/2010 01:26 AM:

Documentation/networking/ip-sysctl.txt max_dgram_qlen - INTEGER · line 1469

Quoted 7 lines

Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC.
IMHO convenient for testing.

Documentation/networking/ip-sysctl.txt +4 -0
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	Default: 16000

1) For lower payload and enough memory, it's not necessary to force garbage collection. So set it to 0, disable gc.

2) Copy your patch to the mail, for other guys to review it.

Signature · 3 lines
Best Regards
-----
Shan Wei
author
#2 lore raw

Re: [PATCH] Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC v.3

Quoted 11 lines · Shan Wei

Pavel Vasilyev wrote, at 12/10/2010 01:26 AM:

Review

Quoted 7 lines

Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC.
IMHO convenient for testing.

(quoted diff) +4 -0
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	Default: 16000

1) For lower payload and enough memory, it's not necessary to force garbage collection. So set it to 0, disable gc.

May be, set default to 2000, and zero to disable

Quoted 1 line

2) Copy your patch to the mail, for other guys to review it.

Where me find other guys? :)

Signature · 1 line
                                                         Pavel.
 
 Documentation/networking/ip-sysctl.txt |    6 ++++++
 include/net/af_unix.h                  |    1 +
 net/unix/garbage.c    	                |    8 +++++---
 net/unix/sysctl_net_unix.c             |    9 +++++++++
 4 files changed, 21 insertions(+), 3 deletions(-)
Documentation/networking/ip-sysctl.txt +6 -0
index 3c5e465..f0c4b6b 100644
@@ -1463,6 +1463,12 @@ max_dgram_qlen - INTEGER
 
 	Default: 10
 
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	0 - disable force garbage collection.
+
+	Default: 2000
 
 UNDOCUMENTED:
include/net/af_unix.h +1 -0
index 18e5c3f..ea580e4 100644
@@ -15,6 +15,7 @@ extern struct sock *unix_get_socket(struct file *filp);
 #define UNIX_HASH_SIZE	256
 
 extern unsigned int unix_tot_inflight;
+extern unsigned int sysctl_inflight_trigger_gc;
 
 struct unix_address {
 	atomic_t	refcnt;
net/unix/garbage.c +5 -3
index f89f83b..c2f3e98 100644
@@ -94,7 +94,7 @@ static DEFINE_SPINLOCK(unix_gc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
 
 unsigned int unix_tot_inflight;
-
+unsigned int sysctl_inflight_trigger_gc = 2000;
 
 struct sock *unix_get_socket(struct file *filp)
 {

@@ -259,7 +259,6 @@ static void inc_inflight_move_tail(struct unix_sock *u)
 }
 
 static bool gc_in_progress = false;
-#define UNIX_INFLIGHT_TRIGGER_GC 16000
 
 void wait_for_unix_gc(void)
 {

@@ -267,8 +266,11 @@ void wait_for_unix_gc(void)
 	 * If number of inflight sockets is insane,
 	 * force a garbage collect right now.
 	 */
-	if (unix_tot_inflight > UNIX_INFLIGHT_TRIGGER_GC && !gc_in_progress)
+	if (!sysctl_inflight_trigger_gc && 
+		    (unix_tot_inflight > sysctl_inflight_trigger_gc 
+					&& !gc_in_progress))
 		unix_gc();
+
 	wait_event(unix_gc_wait, gc_in_progress == false);
 }
net/unix/sysctl_net_unix.c +9 -0
index 397cffe..c807235 100644
@@ -23,6 +23,13 @@ static ctl_table unix_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "inflight_trigger_gc",
+		.data		= &sysctl_inflight_trigger_gc,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec
+	},
 	{ }
 };
 

@@ -41,6 +48,8 @@ int __net_init unix_sysctl_register(struct net *net)
 		goto err_alloc;
 
 	table[0].data = &net->unx.sysctl_max_dgram_qlen;
+	table[1].data = &sysctl_inflight_trigger_gc;
+
 	net->unx.ctl = register_net_sysctl_table(net, unix_path, table);
 	if (net->unx.ctl == NULL)
 		goto err_reg;

---

Signed-off-by Pavel Vasilyev <[email protected]>
#3 lore raw

Re: [PATCH] Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC v.3

Quoted 14 lines · Pavel Vasilyev
Quoted 11 lines · Shan Wei

Pavel Vasilyev wrote, at 12/10/2010 01:26 AM:

Documentation/networking/ip-sysctl.txt max_dgram_qlen - INTEGER

Quoted 7 lines

Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC.
IMHO convenient for testing.

Documentation/networking/ip-sysctl.txt +4 -0
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	Default: 16000

1) For lower payload and enough memory, it's not necessary to force garbage collection. So set it to 0, disable gc.

Quoted 2 lines

May be, set default to 2000, and zero to disable

zero to disable ?

Maybe you missed commit 9915672d41273f5b77 intent.

If you have no limit (like old kernels), you can freeze your machine, even if it has terabytes of ram, running a single program, even as a non root user.

When we discussed about the fix, we said a limit was needed, obviously.

Now you'll have to prove we need to make it a sysctl (yet another /proc/sys/net parameter, yet another documentation to add...)

Even changing default from 16000 to 2000 must be for a valid reason (a real use case)

maintainer
#4 lore raw

Re: [PATCH] Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC v.3

From: Eric Dumazet <[email protected]>
Date: Fri, 10 Dec 2010 14:04:33 +0100

Quoted 26 lines · Pavel Vasilyev
Quoted 14 lines · Shan Wei
Quoted 11 lines

Pavel Vasilyev wrote, at 12/10/2010 01:26 AM:

Documentation/networking/ip-sysctl.txt max_dgram_qlen - INTEGER

Quoted 7 lines

Sysctl interface to UNIX_INFLIGHT_TRIGGER_GC.
IMHO convenient for testing.

Documentation/networking/ip-sysctl.txt +4 -0
+inflight_trigger_gc - INTEGER
+	The maximal number of inflight sockets for force garbage collect.
+
+	Default: 16000

1) For lower payload and enough memory, it's not necessary to force garbage collection. So set it to 0, disable gc.

Quoted 2 lines

May be, set default to 2000, and zero to disable

zero to disable ?

Maybe you missed commit 9915672d41273f5b77 intent.

If you have no limit (like old kernels), you can freeze your machine, even if it has terabytes of ram, running a single program, even as a non root user.

Quoted 7 lines

When we discussed about the fix, we said a limit was needed, obviously.

Now you'll have to prove we need to make it a sysctl (yet another /proc/sys/net parameter, yet another documentation to add...)

Even changing default from 16000 to 2000 must be for a valid reason (a real use case)

I don't want to add this sysctl. Exactly because there is no reason to believe that the current value could even need to be changed by anyone.

Once a demonstratable need can be proven and shown beyond a shadow of a doubt, we can consider adding the sysctl.

We have too many damn sysctls as-is.