* [PATCH] tcp: add window scaling support
@ 2015-08-12 15:57 Josef Bacik
2015-08-17 16:15 ` Andrei Borzenkov
0 siblings, 1 reply; 3+ messages in thread
From: Josef Bacik @ 2015-08-12 15:57 UTC (permalink / raw)
To: kernel-team, grub-devel; +Cc: Josef Bacik
Sometimes we have to provision boxes across regions, such as California to
Sweden. The http server has a 10 minute timeout, so if we can't get our 250mb
image transferred fast enough our provisioning fails, which is not ideal. So
add tcp window scaling on open connections and set the window size to 1mb. With
this change we're able to get higher sustained transfers between regions and can
transfer our image in well below 10 minutes. Without this patch we'd time out
every time halfway through the transfer. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
---
grub-core/net/tcp.c | 42 +++++++++++++++++++++++++++++-------------
1 file changed, 29 insertions(+), 13 deletions(-)
diff --git a/grub-core/net/tcp.c b/grub-core/net/tcp.c
index 5da8b11..57a6d4e 100644
--- a/grub-core/net/tcp.c
+++ b/grub-core/net/tcp.c
@@ -106,6 +106,18 @@ struct tcphdr
grub_uint16_t urgent;
} GRUB_PACKED;
+struct tcp_scale_opt {
+ grub_uint8_t kind;
+ grub_uint8_t length;
+ grub_uint8_t scale;
+} GRUB_PACKED;
+
+struct tcp_synhdr {
+ struct tcphdr tcphdr;
+ struct tcp_scale_opt scale_opt;
+ grub_uint8_t padding;
+};
+
struct tcp_pseudohdr
{
grub_uint32_t src;
@@ -555,7 +567,7 @@ grub_net_tcp_open (char *server,
grub_net_tcp_socket_t socket;
static grub_uint16_t in_port = 21550;
struct grub_net_buff *nb;
- struct tcphdr *tcph;
+ struct tcp_synhdr *tcph;
int i;
grub_uint8_t *nbd;
grub_net_link_level_address_t ll_target_addr;
@@ -617,20 +629,24 @@ grub_net_tcp_open (char *server,
}
tcph = (void *) nb->data;
+ grub_memset(tcph, 0, sizeof (*tcph));
socket->my_start_seq = grub_get_time_ms ();
socket->my_cur_seq = socket->my_start_seq + 1;
- socket->my_window = 8192;
- tcph->seqnr = grub_cpu_to_be32 (socket->my_start_seq);
- tcph->ack = grub_cpu_to_be32_compile_time (0);
- tcph->flags = grub_cpu_to_be16_compile_time ((5 << 12) | TCP_SYN);
- tcph->window = grub_cpu_to_be16 (socket->my_window);
- tcph->urgent = 0;
- tcph->src = grub_cpu_to_be16 (socket->in_port);
- tcph->dst = grub_cpu_to_be16 (socket->out_port);
- tcph->checksum = 0;
- tcph->checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP,
- &socket->inf->address,
- &socket->out_nla);
+ socket->my_window = 32768;
+ tcph->tcphdr.seqnr = grub_cpu_to_be32 (socket->my_start_seq);
+ tcph->tcphdr.ack = grub_cpu_to_be32_compile_time (0);
+ tcph->tcphdr.flags = grub_cpu_to_be16_compile_time ((6 << 12) | TCP_SYN);
+ tcph->tcphdr.window = grub_cpu_to_be16 (socket->my_window);
+ tcph->tcphdr.urgent = 0;
+ tcph->tcphdr.src = grub_cpu_to_be16 (socket->in_port);
+ tcph->tcphdr.dst = grub_cpu_to_be16 (socket->out_port);
+ tcph->tcphdr.checksum = 0;
+ tcph->scale_opt.kind = 3;
+ tcph->scale_opt.length = 3;
+ tcph->scale_opt.scale = 5;
+ tcph->tcphdr.checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP,
+ &socket->inf->address,
+ &socket->out_nla);
tcp_socket_register (socket);
--
1.8.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] tcp: add window scaling support
2015-08-12 15:57 [PATCH] tcp: add window scaling support Josef Bacik
@ 2015-08-17 16:15 ` Andrei Borzenkov
2015-08-18 17:48 ` Josef Bacik
0 siblings, 1 reply; 3+ messages in thread
From: Andrei Borzenkov @ 2015-08-17 16:15 UTC (permalink / raw)
To: The development of GNU GRUB, kernel-team; +Cc: Josef Bacik
12.08.2015 18:57, Josef Bacik пишет:
> Sometimes we have to provision boxes across regions, such as California to
> Sweden. The http server has a 10 minute timeout, so if we can't get our 250mb
> image transferred fast enough our provisioning fails, which is not ideal. So
> add tcp window scaling on open connections and set the window size to 1mb. With
> this change we're able to get higher sustained transfers between regions and can
> transfer our image in well below 10 minutes. Without this patch we'd time out
> every time halfway through the transfer. Thanks,
>
I do not think having 1M TCP window by default is good idea. We probably
could make it configurable if there are evidences that it is really
required.
> Signed-off-by: Josef Bacik <jbacik@fb.com>
> ---
> grub-core/net/tcp.c | 42 +++++++++++++++++++++++++++++-------------
> 1 file changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/grub-core/net/tcp.c b/grub-core/net/tcp.c
> index 5da8b11..57a6d4e 100644
> --- a/grub-core/net/tcp.c
> +++ b/grub-core/net/tcp.c
> @@ -106,6 +106,18 @@ struct tcphdr
> grub_uint16_t urgent;
> } GRUB_PACKED;
>
> +struct tcp_scale_opt {
> + grub_uint8_t kind;
> + grub_uint8_t length;
> + grub_uint8_t scale;
> +} GRUB_PACKED;
> +
> +struct tcp_synhdr {
> + struct tcphdr tcphdr;
> + struct tcp_scale_opt scale_opt;
> + grub_uint8_t padding;
> +};
> +
No, this does not scale. Just allocate large enough buffer and use
pointers inside it. We may want to support multiple options at some point.
> struct tcp_pseudohdr
> {
> grub_uint32_t src;
> @@ -555,7 +567,7 @@ grub_net_tcp_open (char *server,
> grub_net_tcp_socket_t socket;
> static grub_uint16_t in_port = 21550;
> struct grub_net_buff *nb;
> - struct tcphdr *tcph;
> + struct tcp_synhdr *tcph;
> int i;
> grub_uint8_t *nbd;
> grub_net_link_level_address_t ll_target_addr;
> @@ -617,20 +629,24 @@ grub_net_tcp_open (char *server,
> }
>
> tcph = (void *) nb->data;
> + grub_memset(tcph, 0, sizeof (*tcph));
> socket->my_start_seq = grub_get_time_ms ();
> socket->my_cur_seq = socket->my_start_seq + 1;
> - socket->my_window = 8192;
> - tcph->seqnr = grub_cpu_to_be32 (socket->my_start_seq);
> - tcph->ack = grub_cpu_to_be32_compile_time (0);
> - tcph->flags = grub_cpu_to_be16_compile_time ((5 << 12) | TCP_SYN);
> - tcph->window = grub_cpu_to_be16 (socket->my_window);
> - tcph->urgent = 0;
> - tcph->src = grub_cpu_to_be16 (socket->in_port);
> - tcph->dst = grub_cpu_to_be16 (socket->out_port);
> - tcph->checksum = 0;
> - tcph->checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP,
> - &socket->inf->address,
> - &socket->out_nla);
> + socket->my_window = 32768;
> + tcph->tcphdr.seqnr = grub_cpu_to_be32 (socket->my_start_seq);
> + tcph->tcphdr.ack = grub_cpu_to_be32_compile_time (0);
> + tcph->tcphdr.flags = grub_cpu_to_be16_compile_time ((6 << 12) | TCP_SYN);
> + tcph->tcphdr.window = grub_cpu_to_be16 (socket->my_window);
> + tcph->tcphdr.urgent = 0;
> + tcph->tcphdr.src = grub_cpu_to_be16 (socket->in_port);
> + tcph->tcphdr.dst = grub_cpu_to_be16 (socket->out_port);
> + tcph->tcphdr.checksum = 0;
> + tcph->scale_opt.kind = 3;
> + tcph->scale_opt.length = 3;
> + tcph->scale_opt.scale = 5;
> + tcph->tcphdr.checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP,
> + &socket->inf->address,
> + &socket->out_nla);
>
> tcp_socket_register (socket);
>
>
There is one more place - grub_net_tcp_accept. Not sure if it ever be
used though.
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] tcp: add window scaling support
2015-08-17 16:15 ` Andrei Borzenkov
@ 2015-08-18 17:48 ` Josef Bacik
0 siblings, 0 replies; 3+ messages in thread
From: Josef Bacik @ 2015-08-18 17:48 UTC (permalink / raw)
To: Andrei Borzenkov, The development of GNU GRUB, kernel-team
On 08/17/2015 09:15 AM, Andrei Borzenkov wrote:
> 12.08.2015 18:57, Josef Bacik пишет:
>> Sometimes we have to provision boxes across regions, such as
>> California to
>> Sweden. The http server has a 10 minute timeout, so if we can't get
>> our 250mb
>> image transferred fast enough our provisioning fails, which is not
>> ideal. So
>> add tcp window scaling on open connections and set the window size to
>> 1mb. With
>> this change we're able to get higher sustained transfers between
>> regions and can
>> transfer our image in well below 10 minutes. Without this patch we'd
>> time out
>> every time halfway through the transfer. Thanks,
>>
>
> I do not think having 1M TCP window by default is good idea. We probably
> could make it configurable if there are evidences that it is really
> required.
Ok I'll add a config option.
>
>> Signed-off-by: Josef Bacik <jbacik@fb.com>
>> ---
>> grub-core/net/tcp.c | 42 +++++++++++++++++++++++++++++-------------
>> 1 file changed, 29 insertions(+), 13 deletions(-)
>>
>> diff --git a/grub-core/net/tcp.c b/grub-core/net/tcp.c
>> index 5da8b11..57a6d4e 100644
>> --- a/grub-core/net/tcp.c
>> +++ b/grub-core/net/tcp.c
>> @@ -106,6 +106,18 @@ struct tcphdr
>> grub_uint16_t urgent;
>> } GRUB_PACKED;
>>
>> +struct tcp_scale_opt {
>> + grub_uint8_t kind;
>> + grub_uint8_t length;
>> + grub_uint8_t scale;
>> +} GRUB_PACKED;
>> +
>> +struct tcp_synhdr {
>> + struct tcphdr tcphdr;
>> + struct tcp_scale_opt scale_opt;
>> + grub_uint8_t padding;
>> +};
>> +
>
> No, this does not scale. Just allocate large enough buffer and use
> pointers inside it. We may want to support multiple options at some point.
Fair enough.
>
>> struct tcp_pseudohdr
>> {
>> grub_uint32_t src;
>> @@ -555,7 +567,7 @@ grub_net_tcp_open (char *server,
>> grub_net_tcp_socket_t socket;
>> static grub_uint16_t in_port = 21550;
>> struct grub_net_buff *nb;
>> - struct tcphdr *tcph;
>> + struct tcp_synhdr *tcph;
>> int i;
>> grub_uint8_t *nbd;
>> grub_net_link_level_address_t ll_target_addr;
>> @@ -617,20 +629,24 @@ grub_net_tcp_open (char *server,
>> }
>>
>> tcph = (void *) nb->data;
>> + grub_memset(tcph, 0, sizeof (*tcph));
>> socket->my_start_seq = grub_get_time_ms ();
>> socket->my_cur_seq = socket->my_start_seq + 1;
>> - socket->my_window = 8192;
>> - tcph->seqnr = grub_cpu_to_be32 (socket->my_start_seq);
>> - tcph->ack = grub_cpu_to_be32_compile_time (0);
>> - tcph->flags = grub_cpu_to_be16_compile_time ((5 << 12) | TCP_SYN);
>> - tcph->window = grub_cpu_to_be16 (socket->my_window);
>> - tcph->urgent = 0;
>> - tcph->src = grub_cpu_to_be16 (socket->in_port);
>> - tcph->dst = grub_cpu_to_be16 (socket->out_port);
>> - tcph->checksum = 0;
>> - tcph->checksum = grub_net_ip_transport_checksum (nb, GRUB_NET_IP_TCP,
>> - &socket->inf->address,
>> - &socket->out_nla);
>> + socket->my_window = 32768;
>> + tcph->tcphdr.seqnr = grub_cpu_to_be32 (socket->my_start_seq);
>> + tcph->tcphdr.ack = grub_cpu_to_be32_compile_time (0);
>> + tcph->tcphdr.flags = grub_cpu_to_be16_compile_time ((6 << 12) |
>> TCP_SYN);
>> + tcph->tcphdr.window = grub_cpu_to_be16 (socket->my_window);
>> + tcph->tcphdr.urgent = 0;
>> + tcph->tcphdr.src = grub_cpu_to_be16 (socket->in_port);
>> + tcph->tcphdr.dst = grub_cpu_to_be16 (socket->out_port);
>> + tcph->tcphdr.checksum = 0;
>> + tcph->scale_opt.kind = 3;
>> + tcph->scale_opt.length = 3;
>> + tcph->scale_opt.scale = 5;
>> + tcph->tcphdr.checksum = grub_net_ip_transport_checksum (nb,
>> GRUB_NET_IP_TCP,
>> + &socket->inf->address,
>> + &socket->out_nla);
>>
>> tcp_socket_register (socket);
>>
>>
>
> There is one more place - grub_net_tcp_accept. Not sure if it ever be
> used though.
So I only care about connections we open, not about connections that are
opened to us which is why I did it this way. If we start to care about
how fast grub can transfer stuff _to_ somebody else we can add it there
as well. Thanks,
Josef
^ permalink raw reply [flat|nested] 3+ messages in thread
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2015-08-17 16:15 ` Andrei Borzenkov
2015-08-18 17:48 ` Josef Bacik
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