Messages in this thread | | | Date | Wed, 25 Aug 2021 10:06:18 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH] net: tcp_drop adds `reason` parameter for tracing v2 |
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On Wed, 25 Aug 2021 09:20:37 -0700 Eric Dumazet wrote: > On Wed, Aug 25, 2021 at 9:04 AM Jakub Kicinski <kuba@kernel.org> wrote: > > On Wed, 25 Aug 2021 08:47:46 -0700 Eric Dumazet wrote: > > > I'd rather use a string. So that we can more easily identify _why_ the > > > packet was drop, without looking at the source code > > > of the exact kernel version to locate line number 1057 > > > > Yeah, the line number seems like a particularly bad idea. Hopefully > > strings won't be problematic, given we can expect most serious users > > to feed the tracepoints via BPF. enum would be more convenient there, > > I'd think. > > > > > You can be sure that we will get reports in the future from users of > > > heavily modified kernels. > > > Having to download a git tree, or apply semi-private patches is a no go. > > > > I'm slightly surprised by this angle. Are there downstream kernels with > > heavily modified TCP other than Google's? > > Not sure why Google is mentioned here ? > Have you ever received a public report about TCP behavior in a Google kernel ?
That's a rhetorical question quite likely, but to be clear - what I meant is that Google is the main contributor to Linux TCP and has the expertise to make changes. I don't know of any others hence the question.
> Over the years, we received hundreds of TCP bug reports on > netdev@vger, where users claim to use kernel version 4.19 (or other), > when in fact they use 4.19.xxx > It takes in general multiple emails exchange before we get a more > realistic version number. > Not to mention distro kernels, or even worse private kernels, which > are not exactly easy to track for us upstream developers.
Right but for backports values come from original patch, enum or string.
I don't mean to dispute your preference tho, if you want strings, strings it is.
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