From: Abhijeet Rastogi <abhijeet.1989@gmail.com>
To: Simon Horman <horms@verge.net.au>, Julian Anastasov <ja@ssi.bg>,
Pablo Neira Ayuso <pablo@netfilter.org>,
Jozsef Kadlecsik <kadlec@netfilter.org>,
Florian Westphal <fw@strlen.de>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org, lvs-devel@vger.kernel.org,
netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
linux-kernel@vger.kernel.org,
Abhijeet Rastogi <abhijeet.1989@gmail.com>
Subject: [PATCH v2] ipvs: increase ip_vs_conn_tab_bits range for 64BIT
Date: Sun, 14 May 2023 13:40:24 -0700 [thread overview]
Message-ID: <20230412-increase_ipvs_conn_tab_bits-v2-1-994c0df018e6@gmail.com> (raw)
Current range [8, 20] is set purely due to historical reasons
because at the time, ~1M (2^20) was considered sufficient.
With this change, 27 is the upper limit for 64-bit, 20 otherwise.
Previous change regarding this limit is here.
Link: https://lore.kernel.org/all/86eabeb9dd62aebf1e2533926fdd13fed48bab1f.1631289960.git.aclaudi@redhat.com/T/#u
Signed-off-by: Abhijeet Rastogi <abhijeet.1989@gmail.com>
---
The conversation for this started at:
https://www.spinics.net/lists/netfilter/msg60995.html
The upper limit for algo is any bit size less than 32, so this
change will allow us to set bit size > 20. Today, it is common to have
RAM available to handle greater than 2^20 connections per-host.
Distros like RHEL already allow setting limits higher than 20.
---
Changes in v2:
- Lower the ranges, 27 for 64bit, 20 otherwise
- Link to v1: https://lore.kernel.org/r/20230412-increase_ipvs_conn_tab_bits-v1-1-60a4f9f4c8f2@gmail.com
---
net/netfilter/ipvs/Kconfig | 26 +++++++++++++-------------
net/netfilter/ipvs/ip_vs_conn.c | 4 ++--
2 files changed, 15 insertions(+), 15 deletions(-)
diff --git a/net/netfilter/ipvs/Kconfig b/net/netfilter/ipvs/Kconfig
index 271da8447b29..aac5d6bd82e6 100644
--- a/net/netfilter/ipvs/Kconfig
+++ b/net/netfilter/ipvs/Kconfig
@@ -44,7 +44,8 @@ config IP_VS_DEBUG
config IP_VS_TAB_BITS
int "IPVS connection table size (the Nth power of 2)"
- range 8 20
+ range 8 20 if !64BIT
+ range 8 27 if 64BIT
default 12
help
The IPVS connection hash table uses the chaining scheme to handle
@@ -52,18 +53,17 @@ config IP_VS_TAB_BITS
reduce conflicts when there are hundreds of thousands of connections
in the hash table.
- Note the table size must be power of 2. The table size will be the
- value of 2 to the your input number power. The number to choose is
- from 8 to 20, the default number is 12, which means the table size
- is 4096. Don't input the number too small, otherwise you will lose
- performance on it. You can adapt the table size yourself, according
- to your virtual server application. It is good to set the table size
- not far less than the number of connections per second multiplying
- average lasting time of connection in the table. For example, your
- virtual server gets 200 connections per second, the connection lasts
- for 200 seconds in average in the connection table, the table size
- should be not far less than 200x200, it is good to set the table
- size 32768 (2**15).
+ Note the table size must be power of 2. The table size will be the value
+ of 2 to the your input number power. The number to choose is from 8 to 27
+ for 64BIT(20 otherwise), the default number is 12, which means the table
+ size is 4096. Don't input the number too small, otherwise you will lose
+ performance on it. You can adapt the table size yourself, according to
+ your virtual server application. It is good to set the table size not far
+ less than the number of connections per second multiplying average lasting
+ time of connection in the table. For example, your virtual server gets
+ 200 connections per second, the connection lasts for 200 seconds in
+ average in the connection table, the table size should be not far less
+ than 200x200, it is good to set the table size 32768 (2**15).
Another note that each connection occupies 128 bytes effectively and
each hash entry uses 8 bytes, so you can estimate how much memory is
diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
index 13534e02346c..e1b9b52909a5 100644
--- a/net/netfilter/ipvs/ip_vs_conn.c
+++ b/net/netfilter/ipvs/ip_vs_conn.c
@@ -1484,8 +1484,8 @@ int __init ip_vs_conn_init(void)
int idx;
/* Compute size and mask */
- if (ip_vs_conn_tab_bits < 8 || ip_vs_conn_tab_bits > 20) {
- pr_info("conn_tab_bits not in [8, 20]. Using default value\n");
+ if (ip_vs_conn_tab_bits < 8 || ip_vs_conn_tab_bits > 27) {
+ pr_info("conn_tab_bits not in [8, 27]. Using default value\n");
ip_vs_conn_tab_bits = CONFIG_IP_VS_TAB_BITS;
}
ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
---
base-commit: 09a9639e56c01c7a00d6c0ca63f4c7c41abe075d
change-id: 20230412-increase_ipvs_conn_tab_bits-4322c90da216
Best regards,
--
Abhijeet Rastogi <abhijeet.1989@gmail.com>
next reply other threads:[~2023-05-14 20:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-14 20:40 Abhijeet Rastogi [this message]
2023-05-15 15:18 ` [PATCH v2] ipvs: increase ip_vs_conn_tab_bits range for 64BIT Julian Anastasov
2023-05-16 1:46 ` Abhijeet Rastogi
2023-05-16 5:35 ` Julian Anastasov
2023-05-17 3:10 ` Abhijeet Rastogi
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