On Tue, Jan 02, 2018 at 02:11:25PM -0500, Neal Cardwell wrote:
On Tue, Jan 2, 2018 at 1:32 PM, David Miller davem@davemloft.net wrote:
From: Neal Cardwell ncardwell@google.com Date: Tue, 2 Jan 2018 11:57:59 -0500
On Mon, Jan 1, 2018 at 9:31 AM, Greg Kroah-Hartman gregkh@linuxfoundation.org wrote:
This is the start of the stable review cycle for the 4.9.74 release. There are 75 patches in this series, all will be posted as a response to this one. If anyone has any issues with these being applied, please let me know.
Responses should be made by Wed Jan 3 14:00:03 UTC 2018. Anything received after that time might be too late.
The whole patch series can be found in one patch at: kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.74-rc1.gz or in the git tree and branch at: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.9.y and the diffstat can be found below.
Hi Greg,
In looking at the 4.9 and 4.14 patches yesterday, I noticed there were two TCP BBR fixes that made it into 4.14 but not 4.9. Doing an inventory of the TCP BBR fixes, AFAICT we have:
c589e69b508d tcp_bbr: record "full bw reached" decision in new full_bw_reached bit
- in 4.9 and 4.14 (great)
2f6c498e4f15 tcp_bbr: reset full pipe detection on loss recovery undo
- in 4.14 (but not 4.9)
600647d467c6 tcp_bbr: reset long-term bandwidth sampling on loss recovery undo
- in 4.14 (but not 4.9)
Lacking the second and third patches in 4.9 will not cause any new problems, but it will miss out on some nice fixes. If it's possible to get 2f6c498e4f15 and 600647d467c6 either into 4.9.74 or 4.9.75, I would be very grateful.
These were not straight-forward to backport and I felt the risk outweighed the gains.
If you want to do the backport yourself and you feel confident in it, feel free.
Thanks, Greg and David. Looks like these 2 patches will cherry-pick cleanly if cherry-picked in the following sequence, on top of 4.9.74-rc1, which already has 6c9e73ef9aa7 ("tcp_bbr: record "full bw reached" decision in new full_bw_reached bit"):
$ git checkout linux-stable-rc/linux-4.9.y
$ git cherry-pick 2f6c498e4f15 Performing inexact rename detection: 100% (17803152/17803152), done. [detached HEAD 0982234c57e1] tcp_bbr: reset full pipe detection on loss recovery undo Date: Thu Dec 7 12:43:31 2017 -0500 1 file changed, 4 insertions(+)
$ git cherry-pick 600647d467c6 Performing inexact rename detection: 100% (17803152/17803152), done. [detached HEAD 7e866eccd083] tcp_bbr: reset long-term bandwidth sampling on loss recovery undo Date: Thu Dec 7 12:43:32 2017 -0500 1 file changed, 1 insertion(+)
$ git log --oneline --decorate | head -3 7e866eccd083 (HEAD) tcp_bbr: reset long-term bandwidth sampling on loss recovery undo 0982234c57e1 tcp_bbr: reset full pipe detection on loss recovery undo 79070be7f1ae (linux-stable-rc/linux-4.9.y) Linux 4.9.74-rc1
I verified that this compiles without warnings, and boots, and BBR works.
Shall I prepare another version of these 2 patches, or do we think this recipe will be sufficient? (Sorry I am not more familiar with the backport-to-stable process.)
That works, those two patches are now queued up for the next stable release, thanks!
greg k-h