diff mbox series

[1/3] tcp: export symbol tcp_set_congestion_control

Message ID 20220311030113.73384-2-sunmingbao@tom.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series NVMe/TCP: support specifying the congestion-control | expand

Checks

Context Check Description
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 4 this patch: 4
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 9 this patch: 9
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 7 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Mingbao Sun March 11, 2022, 3:01 a.m. UTC 
From: Mingbao Sun <tyler.sun@dell.com>

congestion-control could have a noticeable impaction on the
performance of TCP-based communications. This is of course true
to NVMe/TCP in the kernel.

Different congestion-controls (e.g., cubic, dctcp) are suitable for
different scenarios. Proper adoption of congestion control would
benefit the performance. On the contrary, the performance could be
destroyed.

So to gain excellent performance against different network
environments, NVMe/TCP tends to support specifying the
congestion-control.

This means NVMe/TCP (a kernel user) needs to set the congestion-control
of its TCP sockets.

Since the kernel API 'kernel_setsockopt' was removed, and since the
function ‘tcp_set_congestion_control’ is just the real underlying guy
handling this job, so it makes sense to get it exported.

Signed-off-by: Mingbao Sun <tyler.sun@dell.com>
---
 net/ipv4/tcp_cong.c | 1 +
 1 file changed, 1 insertion(+)

Comments

Christoph Hellwig March 11, 2022, 7:13 a.m. UTC | #1 
Maybe add a kerneldoc comment now that this is an exported API?

Otherwise this looks fine to me:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Mingbao Sun March 11, 2022, 8:39 a.m. UTC | #2 
On Fri, 11 Mar 2022 08:13:19 +0100
Christoph Hellwig <hch@lst.de> wrote:

> Maybe add a kerneldoc comment now that this is an exported API?
> 
> Otherwise this looks fine to me:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

accept.

will add it in the next version.
and will notice user "Must be called on a locked sock".
diff mbox series

Patch

diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index db5831e6c136..5d77f3e7278e 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -383,6 +383,7 @@  int tcp_set_congestion_control(struct sock *sk, const char *name, bool load,
 	rcu_read_unlock();
 	return err;
 }
+EXPORT_SYMBOL_GPL(tcp_set_congestion_control);
 
 /* Slow start is used when congestion window is no greater than the slow start
  * threshold. We base on RFC2581 and also handle stretch ACKs properly.