Date: Thu, 11 Oct 2018 22:11:36 -0700 From: Ryan Moeller <ryan@ixsystems.com> To: net@freebsd.org Subject: 11-stable TCP reassembly queue Message-ID: <C6EB3FF8-33E4-43D3-B388-CDEA15570AC6@ixsystems.com>
next in thread | raw e-mail | index | archive | help
There are some reports of network dropouts associated with the max TCP = reassembly queue length: = https://forums.freenas.org/index.php?threads/11-1u6-update-transfer-aborts= -on-smb-share-mac-client.69553/ = <https://forums.freenas.org/index.php?threads/11-1u6-update-transfer-abort= s-on-smb-share-mac-client.69553/> = https://forums.freenas.org/index.php?threads/network-issues-after-upgradin= g-to-11-1-u6.69506/ = <https://forums.freenas.org/index.php?threads/network-issues-after-upgradi= ng-to-11-1-u6.69506/> I am aware that a sysctl can be adjusted to increase the maximum queue = length if needed. However, I am curious if the default might be a bit = low. Can anyone offer some advice on how to determine a rational limit = to set? To offer an additional data point: on my own desktop system = (11.2-RELEASE-p2) there are currently 3191 discarded segments. I'm not = sure if this is an unusually high number, and I honestly wouldn't have = realized it was happening if I hadn=E2=80=99t been looking at my own = stats out of curiosity. The most significant network activity for this = machine is fetching code from GitHub or downloading package updates. I = occasionally scp files to/from a macOS laptop over wifi. It seems a bit odd that my moderate traffic would be exceeding the = default threshold at all. Is this to be expected? I saw the TCP reassembly improvements in = https://reviews.freebsd.org/D16471 <https://reviews.freebsd.org/D16471>; = and wonder if this is perhaps related. Finally, I see that a rewrite of the TCP reassembly code addressing the = inefficiency underlying the original security concern has been committed = to 12-CURRENT, and this is great for FreeBSD 12+, but it seems like it = probably won=E2=80=99t be merged into the stable branches. Can anyone = confirm that is the case? Thanks, Ryan Moeller=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C6EB3FF8-33E4-43D3-B388-CDEA15570AC6>