From: Kumar S <ps2kumar@yahoo.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "netdev@vger.kernel.org" <netdev@vger.kernel.org>
Subject: Re: Memory leak in ip_dst_cache
Date: Fri, 9 Sep 2011 13:48:03 -0700 (PDT) [thread overview]
Message-ID: <1315601283.91185.YahooMailNeo@web113908.mail.gq1.yahoo.com> (raw)
In-Reply-To: <1315596786.2606.3.camel@edumazet-laptop>
Hi Eric,
I did not flush those routes explicitly. They are flushed out automatically by calling "rt_run_flush". It inturn calls rt_free(), but __cache_free() never gets called after that. Basically, I have 512 MBytes of memory on board. I want to restrict the cache to around 64k, with max_size. But if I do that due to this leak, TCP/IP communication stops working when it reaches 64k.
Thanks
psk
----- Original Message -----
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Kumar S <ps2kumar@yahoo.com>
Cc:
Sent: Friday, September 9, 2011 12:33 PM
Subject: Re: Memory leak in ip_dst_cache
Le vendredi 09 septembre 2011 à 11:39 -0700, Kumar S a écrit :
> Hi Eric,
> Thanks for the response. Here is the output of the commands you mentioned.
>
Hmm, you should have included netdev in this message.
> After injecting around11k routes:
> -sh-2.05b#
> -sh-2.05b# ip route ls cache | wc
> 23256 162772 1166903
> -sh-2.05b#
>
> After route flush out:
>
> -sh-2.05b#
> -sh-2.05b# ip route ls cache | wc
> 14 88 710
> -sh-2.05b#
> -sh-2.05b#
> -sh-2.05b#
> -sh-2.05b# cat /proc/slabinfo | grep ip_dst
> ip_dst_cache 11673 11685 256 15 1 : tunables 120 60 0 : slabdata 779 779 0
Thats OK : Each tcp session has a pointer to a dst.
When you "ip route flush cache", busy dst are all invalidated.
"ip route ls cache" doesnt output invalidated dsts.
As soon as tcp session will try to send a packet, it will notice the dst
is obsolete and 'free' it.
> -sh-2.05b#
> -sh-2.05b# grep . /proc/sys/net/ipv4/route/*
> /proc/sys/net/ipv4/route/error_burst:1250
> /proc/sys/net/ipv4/route/error_cost:250
> grep: /proc/sys/net/ipv4/route/flush: Permission denied
> /proc/sys/net/ipv4/route/gc_elasticity:8
> /proc/sys/net/ipv4/route/gc_interval:60
> /proc/sys/net/ipv4/route/gc_min_interval:0
> /proc/sys/net/ipv4/route/gc_min_interval_ms:500
> /proc/sys/net/ipv4/route/gc_thresh:16384
> /proc/sys/net/ipv4/route/gc_timeout:300
> /proc/sys/net/ipv4/route/max_delay:10
> /proc/sys/net/ipv4/route/max_size:2097152
> /proc/sys/net/ipv4/route/min_adv_mss:256
> /proc/sys/net/ipv4/route/min_delay:2
> /proc/sys/net/ipv4/route/min_pmtu:552
> /proc/sys/net/ipv4/route/mtu_expires:600
> /proc/sys/net/ipv4/route/redirect_load:5
> /proc/sys/net/ipv4/route/redirect_number:9
> /proc/sys/net/ipv4/route/redirect_silence:5120
> /proc/sys/net/ipv4/route/secret_interval:600
> -sh-2.05b# rtstat -c10 -i1
> rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|rt_cache|
> entries| in_hit|in_slow_|in_slow_|in_no_ro| in_brd|in_marti|in_marti| out_hit|out_slow|out_slow|gc_total|gc_ignor|gc_goal_|gc_dst_o|in_hlist|out_hlis|
> | | tot| mc| ute| | an_dst| an_src| | _tot| _mc| | ed| miss| verflow| _search|t_search|
> 11675| 27700| 101014| 0| 0| 130| 0| 0| 36284| 23436| 0| 0| 0| 0| 0| 9658| 23140|
> 11675| 6| 18| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 2| 10| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 8| 18| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 6| 18| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 4| 16| 0| 0| 0| 0| 0| 4| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 8| 12| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 6| 10| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 2| 14| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> 11675| 8| 12| 0| 0| 0| 0| 0| 2| 0| 0| 0| 0| 0| 0| 0| 0|
> -sh-2.05b#
>
>
Thats pretty low ip route usage, you dont need to tweak your tunables.
Thanks
next prev parent reply other threads:[~2011-09-09 20:54 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-09 5:04 Memory leak in ip_dst_cache Kumar S
2011-09-09 5:30 ` Eric Dumazet
[not found] ` <1315593553.98279.YahooMailNeo@web113904.mail.gq1.yahoo.com>
[not found] ` <1315596786.2606.3.camel@edumazet-laptop>
2011-09-09 20:48 ` Kumar S [this message]
2011-09-09 21:47 ` Eric Dumazet
[not found] ` <1315605497.25052.YahooMailNeo@web113916.mail.gq1.yahoo.com>
2011-09-09 22:08 ` Eric Dumazet
2011-09-09 22:53 ` Kumar S
2011-09-10 13:04 ` Neil Horman
2011-09-12 3:38 ` Kumar S
2011-09-12 5:40 ` Eric Dumazet
2011-09-12 6:07 ` Kumar S
2011-09-12 6:28 ` Eric Dumazet
2011-09-12 17:16 ` Kumar S
2011-09-12 17:57 ` Eric Dumazet
2011-09-12 22:20 ` Kumar S
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