From: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> To: unlisted-recipients:; (no To-header on input) Cc: "Hans Westgaard Ry" <hans.westgaard.ry@oracle.com>, "David S. Miller" <davem@davemloft.net>, "Alexey Kuznetsov" <kuznet@ms2.inr.ac.ru>, "James Morris" <jmorris@namei.org>, "Hideaki YOSHIFUJI" <yoshfuji@linux-ipv6.org>, "Patrick McHardy" <kaber@trash.net>, "Tom Herbert" <tom@herbertland.com>, "Pablo Neira Ayuso" <pablo@netfilter.org>, "Eric Dumazet" <edumazet@google.com>, "Florian Westphal" <fw@strlen.de>, "Jiri Pirko" <jiri@resnulli.us>, "Alexander Duyck" <alexander.h.duyck@redhat.com>, "Michal Hocko" <mhocko@suse.com>, "Linus Lüssing" <linus.luessing@c0d3.blue>, "Hannes Frederic Sowa" <hannes@stressinduktion.org>, "Herbert Xu" <herbert@gondor.apana.org.au>, "Tejun Heo" <tj@kernel.org>, "Andrew Morton" <akpm@linux-foundation.org>, "Alexey Kodanev" <alexey.kodanev@oracle.com>, "Håkon Bugge" <haakon.bugge@oracle.com>, linux-kernel@vger.kernel.org (open list), netdev@vger.kernel.org (open list:NETWORKING [GENERAL]) Subject: [PATCH v3] net:Add sysctl_max_skb_frags Date: Wed, 3 Feb 2016 09:26:57 +0100 [thread overview] Message-ID: <1454488017-8822-1-git-send-email-hans.westgaard.ry@oracle.com> (raw) In-Reply-To: <568F87AC.60405@oracle.com> Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 2 ++ net/core/sysctl_net_core.c | 10 ++++++++++ net/ipv4/tcp.c | 4 ++-- 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4355129..fe47ad3 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -219,6 +219,7 @@ struct sk_buff; #else #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) #endif +extern int sysctl_max_skb_frags; typedef struct skb_frag_struct skb_frag_t; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 152b9c7..c336b97 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -79,6 +79,8 @@ struct kmem_cache *skbuff_head_cache __read_mostly; static struct kmem_cache *skbuff_fclone_cache __read_mostly; +int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; +EXPORT_SYMBOL(sysctl_max_skb_frags); /** * skb_panic - private function for out-of-line support diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 95b6139..a6beb7b 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -26,6 +26,7 @@ static int zero = 0; static int one = 1; static int min_sndbuf = SOCK_MIN_SNDBUF; static int min_rcvbuf = SOCK_MIN_RCVBUF; +static int max_skb_frags = MAX_SKB_FRAGS; static int net_msg_warn; /* Unused, but still a sysctl */ @@ -392,6 +393,15 @@ static struct ctl_table net_core_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "max_skb_frags", + .data = &sysctl_max_skb_frags, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, + .extra2 = &max_skb_frags, + }, { } }; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c82cca1..3dc7a2fd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -938,7 +938,7 @@ new_segment: i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= MAX_SKB_FRAGS) { + if (!can_coalesce && i >= sysctl_max_skb_frags) { tcp_mark_push(tp, skb); goto new_segment; } @@ -1211,7 +1211,7 @@ new_segment: if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i == MAX_SKB_FRAGS || !sg) { + if (i == sysctl_max_skb_frags || !sg) { tcp_mark_push(tp, skb); goto new_segment; } -- 2.4.3
WARNING: multiple messages have this Message-ID (diff)
From: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> To: unlisted-recipients:; (no To-header on input) Cc: "Hans Westgaard Ry" <hans.westgaard.ry@oracle.com>, "David S. Miller" <davem@davemloft.net>, "Alexey Kuznetsov" <kuznet@ms2.inr.ac.ru>, "James Morris" <jmorris@namei.org>, "Hideaki YOSHIFUJI" <yoshfuji@linux-ipv6.org>, "Patrick McHardy" <kaber@trash.net>, "Tom Herbert" <tom@herbertland.com>, "Pablo Neira Ayuso" <pablo@netfilter.org>, "Eric Dumazet" <edumazet@google.com>, "Florian Westphal" <fw@strlen.de>, "Jiri Pirko" <jiri@resnulli.us>, "Alexander Duyck" <alexander.h.duyck@redhat.com>, "Michal Hocko" <mhocko@suse.com>, "Linus Lüssing" <linus.luessing@c0d3.blue>, "Hannes Frederic Sowa" <hannes@stressinduktion.org>, "Herbert Xu" <herbert@gondor.apana.org.au>, "Tejun Heo" <tj@kernel.org>, "Andrew Morton" <akpm@linux-foundation.org>, "Alexey Kodanev" <alexey.kodanev@oracle.com>, "Håkon Bugge" <haakon.bugge@oracle.com>, linux-kernel@vger.kernel.org (open list) Subject: [PATCH v3] net:Add sysctl_max_skb_frags Date: Wed, 3 Feb 2016 09:26:57 +0100 [thread overview] Message-ID: <1454488017-8822-1-git-send-email-hans.westgaard.ry@oracle.com> (raw) In-Reply-To: <568F87AC.60405@oracle.com> Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> --- include/linux/skbuff.h | 1 + net/core/skbuff.c | 2 ++ net/core/sysctl_net_core.c | 10 ++++++++++ net/ipv4/tcp.c | 4 ++-- 4 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 4355129..fe47ad3 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -219,6 +219,7 @@ struct sk_buff; #else #define MAX_SKB_FRAGS (65536/PAGE_SIZE + 1) #endif +extern int sysctl_max_skb_frags; typedef struct skb_frag_struct skb_frag_t; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 152b9c7..c336b97 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -79,6 +79,8 @@ struct kmem_cache *skbuff_head_cache __read_mostly; static struct kmem_cache *skbuff_fclone_cache __read_mostly; +int sysctl_max_skb_frags __read_mostly = MAX_SKB_FRAGS; +EXPORT_SYMBOL(sysctl_max_skb_frags); /** * skb_panic - private function for out-of-line support diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 95b6139..a6beb7b 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -26,6 +26,7 @@ static int zero = 0; static int one = 1; static int min_sndbuf = SOCK_MIN_SNDBUF; static int min_rcvbuf = SOCK_MIN_RCVBUF; +static int max_skb_frags = MAX_SKB_FRAGS; static int net_msg_warn; /* Unused, but still a sysctl */ @@ -392,6 +393,15 @@ static struct ctl_table net_core_table[] = { .mode = 0644, .proc_handler = proc_dointvec }, + { + .procname = "max_skb_frags", + .data = &sysctl_max_skb_frags, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = &one, + .extra2 = &max_skb_frags, + }, { } }; diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index c82cca1..3dc7a2fd 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -938,7 +938,7 @@ new_segment: i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= MAX_SKB_FRAGS) { + if (!can_coalesce && i >= sysctl_max_skb_frags) { tcp_mark_push(tp, skb); goto new_segment; } @@ -1211,7 +1211,7 @@ new_segment: if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i == MAX_SKB_FRAGS || !sg) { + if (i == sysctl_max_skb_frags || !sg) { tcp_mark_push(tp, skb); goto new_segment; } -- 2.4.3
next prev parent reply other threads:[~2016-02-03 8:29 UTC|newest] Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-01-06 13:16 [PATCH] net: add per device sg_max_frags for skb Hans Westgaard Ry 2016-01-06 13:16 ` Hans Westgaard Ry 2016-01-06 13:59 ` David Laight 2016-01-06 13:59 ` David Laight 2016-01-08 9:55 ` Hans Westgaard Ry 2016-01-08 9:55 ` Hans Westgaard Ry 2016-01-08 10:33 ` David Laight 2016-01-08 10:33 ` David Laight 2016-01-08 11:47 ` Hannes Frederic Sowa 2016-01-08 11:47 ` Hannes Frederic Sowa 2016-01-13 13:57 ` Hans Westgaard Ry 2016-01-13 13:57 ` Hans Westgaard Ry 2016-01-13 14:19 ` Eric Dumazet 2016-01-13 14:19 ` Eric Dumazet 2016-01-13 14:20 ` Eric Dumazet 2016-01-13 14:20 ` Eric Dumazet 2016-01-13 15:07 ` Hannes Frederic Sowa 2016-01-13 15:07 ` Hannes Frederic Sowa 2016-01-13 15:38 ` David Miller 2016-01-13 15:44 ` Eric Dumazet 2016-01-13 15:44 ` Eric Dumazet 2016-01-13 21:07 ` Eric W. Biederman 2016-01-13 21:07 ` Eric W. Biederman 2016-01-27 13:20 ` [PATCH v2] net:Add sysctl_tcp_sg_max_skb_frags Hans Westgaard Ry 2016-01-27 15:15 ` Eric Dumazet 2016-01-27 18:12 ` Hannes Frederic Sowa 2016-02-01 13:12 ` Hans Westgaard Ry 2016-01-27 20:13 ` David Miller 2016-02-03 8:26 ` Hans Westgaard Ry [this message] 2016-02-03 8:26 ` [PATCH v3] net:Add sysctl_max_skb_frags Hans Westgaard Ry 2016-02-03 11:25 ` Herbert Xu 2016-02-03 11:36 ` Hannes Frederic Sowa 2016-02-03 12:20 ` Herbert Xu 2016-02-03 14:03 ` Hannes Frederic Sowa 2016-02-03 14:30 ` Eric Dumazet 2016-02-03 14:30 ` Eric Dumazet 2016-02-03 17:36 ` David Laight 2016-02-03 15:58 ` Alexander Duyck 2016-02-03 16:07 ` Eric Dumazet 2016-02-03 16:07 ` Eric Dumazet 2016-02-03 17:43 ` Alexander Duyck 2016-02-03 17:43 ` Alexander Duyck 2016-02-03 17:54 ` Eric Dumazet 2016-02-03 17:54 ` Eric Dumazet 2016-02-03 18:24 ` Alexander Duyck 2016-02-03 18:24 ` Alexander Duyck 2016-02-03 19:23 ` Eric Dumazet 2016-02-03 19:23 ` Eric Dumazet 2016-02-03 21:03 ` Alexander Duyck 2016-02-09 9:30 ` David Miller 2016-01-06 14:05 ` [PATCH] net: add per device sg_max_frags for skb Eric Dumazet 2016-01-06 14:05 ` Eric Dumazet 2016-01-08 10:01 ` Hans Westgaard Ry 2016-01-08 10:01 ` Hans Westgaard Ry
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1454488017-8822-1-git-send-email-hans.westgaard.ry@oracle.com \ --to=hans.westgaard.ry@oracle.com \ --cc=akpm@linux-foundation.org \ --cc=alexander.h.duyck@redhat.com \ --cc=alexey.kodanev@oracle.com \ --cc=davem@davemloft.net \ --cc=edumazet@google.com \ --cc=fw@strlen.de \ --cc=haakon.bugge@oracle.com \ --cc=hannes@stressinduktion.org \ --cc=herbert@gondor.apana.org.au \ --cc=jiri@resnulli.us \ --cc=jmorris@namei.org \ --cc=kaber@trash.net \ --cc=kuznet@ms2.inr.ac.ru \ --cc=linus.luessing@c0d3.blue \ --cc=linux-kernel@vger.kernel.org \ --cc=mhocko@suse.com \ --cc=netdev@vger.kernel.org \ --cc=pablo@netfilter.org \ --cc=tj@kernel.org \ --cc=tom@herbertland.com \ --cc=yoshfuji@linux-ipv6.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.