diff mbox

[v2] IPVS: logging sizeof(struct ip_vs_conn) on startup

Message ID 20090727131357.9561.39720.stgit@jazzy.zrh.corp.google.com
State Rejected, archived
Delegated to: David Miller
Headers show

Commit Message

Hannes Eder July 27, 2009, 1:13 p.m. UTC 
No more guessing, how much memory used by IPVS for a connection.

[ The number printed is a lower bound, as ip_vs_conn_cache uses
SLAB_HWCACHE_ALIGN. ]

Signed-off-by: Hannes Eder <heder@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>

 net/netfilter/ipvs/ip_vs_core.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)


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Comments

David Miller July 27, 2009, 6:48 p.m. UTC | #1 
From: Hannes Eder <heder@google.com>
Date: Mon, 27 Jul 2009 15:13:57 +0200

> No more guessing, how much memory used by IPVS for a connection.
> 
> [ The number printed is a lower bound, as ip_vs_conn_cache uses
> SLAB_HWCACHE_ALIGN. ]
> 
> Signed-off-by: Hannes Eder <heder@google.com>
> Signed-off-by: Simon Horman <horms@verge.net.au>

Who needs to know this?  A developer?

They can run tools such as 'pahole' et al. to fish out this
information even when only a kernel binary is available.

For the user, it's just noise.

I'm not applying this, sorry.
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Simon Horman July 28, 2009, 12:19 a.m. UTC | #2 
On Mon, Jul 27, 2009 at 11:48:45AM -0700, David Miller wrote:
> From: Hannes Eder <heder@google.com>
> Date: Mon, 27 Jul 2009 15:13:57 +0200
> 
> > No more guessing, how much memory used by IPVS for a connection.
> > 
> > [ The number printed is a lower bound, as ip_vs_conn_cache uses
> > SLAB_HWCACHE_ALIGN. ]
> > 
> > Signed-off-by: Hannes Eder <heder@google.com>
> > Signed-off-by: Simon Horman <horms@verge.net.au>
> 
> Who needs to know this?  A developer?
> 
> They can run tools such as 'pahole' et al. to fish out this
> information even when only a kernel binary is available.
> 
> For the user, it's just noise.
> 
> I'm not applying this, sorry.

Surprisingly its a very common question amongst users,
because they want to know how much memory they need.
It is of course all a bit silly, because the amount of
memory used by the connection table is usually very small,
but people still ask.

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Eric Dumazet July 28, 2009, 5:38 a.m. UTC | #3 
Simon Horman a écrit :
> 
> Surprisingly its a very common question amongst users,
> because they want to know how much memory they need.
> It is of course all a bit silly, because the amount of
> memory used by the connection table is usually very small,
> but people still ask.
> 

If SLUB is used 

$ cat /sys/kernel/slab/ip_vs_conn/object_size

If SLAB is used, take fourth column of :

$ grep ip_vs_conn /proc/slabinfo

BTW these take into account L1 cache size alignment
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diff mbox

Patch

diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index b021464..b6bb4a0 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -1475,7 +1475,8 @@  static int __init ip_vs_init(void)
 		goto cleanup_conn;
 	}
 
-	IP_VS_INFO("ipvs loaded.\n");
+	IP_VS_INFO("ipvs loaded (using at least %Zd bytes/connection).\n",
+	       sizeof(struct ip_vs_conn));
 	return ret;
 
   cleanup_conn: