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[ipsec-next,0/2] xfrm interface: use hash to store xfrmi contexts

Message ID 20200709101652.1911784-1-eyal.birger@gmail.com
Headers show
Series xfrm interface: use hash to store xfrmi contexts | expand

Message

Eyal Birger July 9, 2020, 10:16 a.m. UTC
When having many xfrm interfaces, the linear lookup of devices based on
if_id becomes costly.

The first patch refactors xfrmi_decode_session() to use the xi used in
the netdevice priv context instead of looking it up in the list based
on ifindex. This is needed in order to use if_id as the only key used
for xi lookup.

The second patch extends the existing infrastructure - which already
stores the xfrmi contexts in an array of lists - to use a hash of the
if_id.

Example benchmarks:
- running on a KVM based VM
- xfrm tunnel mode between two namespaces
- xfrm interface in one namespace (10.0.0.2)

Before this change set:

Single xfrm interface in namespace:
$ netperf -H 10.0.0.2 -l8 -I95,10 -t TCP_STREAM

MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.2 () port 0 AF_INET : +/-5.000% @ 95% conf.  : demo
Recv   Send    Send                          
Socket Socket  Message  Elapsed              
Size   Size    Size     Time     Throughput  
bytes  bytes   bytes    secs.    10^6bits/sec  

131072  16384  16384    8.00      298.36

After adding 400 xfrmi interfaces in the same namespace:

$ netperf -H 10.0.0.2 -l8 -I95,10 -t TCP_STREAM

MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.2 () port 0 AF_INET : +/-5.000% @ 95% conf.  : demo
Recv   Send    Send                          
Socket Socket  Message  Elapsed              
Size   Size    Size     Time     Throughput  
bytes  bytes   bytes    secs.    10^6bits/sec  

131072  16384  16384    8.00      221.77   

After this patchset there was no observed change after adding the
xfrmi interfaces.

Eyal Birger (2):
  xfrm interface: avoid xi lookup in xfrmi_decode_session()
  xfrm interface: store xfrmi contexts in a hash by if_id

 net/xfrm/xfrm_interface.c | 52 +++++++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 19 deletions(-)

Comments

Steffen Klassert July 14, 2020, 9:44 a.m. UTC | #1
On Thu, Jul 09, 2020 at 01:16:50PM +0300, Eyal Birger wrote:
> When having many xfrm interfaces, the linear lookup of devices based on
> if_id becomes costly.
> 
> The first patch refactors xfrmi_decode_session() to use the xi used in
> the netdevice priv context instead of looking it up in the list based
> on ifindex. This is needed in order to use if_id as the only key used
> for xi lookup.
> 
> The second patch extends the existing infrastructure - which already
> stores the xfrmi contexts in an array of lists - to use a hash of the
> if_id.
> 
> Example benchmarks:
> - running on a KVM based VM
> - xfrm tunnel mode between two namespaces
> - xfrm interface in one namespace (10.0.0.2)
> 
> Before this change set:
> 
> Single xfrm interface in namespace:
> $ netperf -H 10.0.0.2 -l8 -I95,10 -t TCP_STREAM
> 
> MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.2 () port 0 AF_INET : +/-5.000% @ 95% conf.  : demo
> Recv   Send    Send                          
> Socket Socket  Message  Elapsed              
> Size   Size    Size     Time     Throughput  
> bytes  bytes   bytes    secs.    10^6bits/sec  
> 
> 131072  16384  16384    8.00      298.36
> 
> After adding 400 xfrmi interfaces in the same namespace:
> 
> $ netperf -H 10.0.0.2 -l8 -I95,10 -t TCP_STREAM
> 
> MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.2 () port 0 AF_INET : +/-5.000% @ 95% conf.  : demo
> Recv   Send    Send                          
> Socket Socket  Message  Elapsed              
> Size   Size    Size     Time     Throughput  
> bytes  bytes   bytes    secs.    10^6bits/sec  
> 
> 131072  16384  16384    8.00      221.77   
> 
> After this patchset there was no observed change after adding the
> xfrmi interfaces.
> 
> Eyal Birger (2):
>   xfrm interface: avoid xi lookup in xfrmi_decode_session()
>   xfrm interface: store xfrmi contexts in a hash by if_id
> 
>  net/xfrm/xfrm_interface.c | 52 +++++++++++++++++++++++++--------------
>  1 file changed, 33 insertions(+), 19 deletions(-)

Applied to ipsec-next, thanks a lot Eyal!