Messages in this thread | | | Date | Mon, 25 Nov 2019 11:25:50 +0300 | From | Alexander Lobakin <> | Subject | Re: [PATCH v2 net-next] net: core: use listified Rx for GRO_NORMAL in napi_gro_receive() |
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Alexander Lobakin wrote 25.11.2019 10:54: > Nicholas Johnson wrote 25.11.2019 10:29: >> Hi, >> >> On Wed, Oct 16, 2019 at 10:31:31AM +0300, Alexander Lobakin wrote: >>> David Miller wrote 16.10.2019 04:16: >>> > From: Alexander Lobakin <alobakin@dlink.ru> >>> > Date: Mon, 14 Oct 2019 11:00:33 +0300 >>> > >>> > > Commit 323ebb61e32b4 ("net: use listified RX for handling GRO_NORMAL >>> > > skbs") made use of listified skb processing for the users of >>> > > napi_gro_frags(). >>> > > The same technique can be used in a way more common napi_gro_receive() >>> > > to speed up non-merged (GRO_NORMAL) skbs for a wide range of drivers >>> > > including gro_cells and mac80211 users. >>> > > This slightly changes the return value in cases where skb is being >>> > > dropped by the core stack, but it seems to have no impact on related >>> > > drivers' functionality. >>> > > gro_normal_batch is left untouched as it's very individual for every >>> > > single system configuration and might be tuned in manual order to >>> > > achieve an optimal performance. >>> > > >>> > > Signed-off-by: Alexander Lobakin <alobakin@dlink.ru> >>> > > Acked-by: Edward Cree <ecree@solarflare.com> >>> > >>> > Applied, thank you. >>> >>> David, Edward, Eric, Ilias, >>> thank you for your time. >>> >>> Regards, >>> ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ >> >> I am very sorry to be the bearer of bad news. It appears that this >> commit is causing a regression in Linux 5.4.0-rc8-next-20191122, >> preventing me from connecting to Wi-Fi networks. I have a Dell XPS >> 9370 >> (Intel Core i7-8650U) with Intel Wireless 8265 [8086:24fd]. > > Hi! > > It's a bit strange as this commit doesn't directly affect the packet > flow. I don't have any iwlwifi hardware at the moment, so let's see if > anyone else will be able to reproduce this (for now, it is the first > report in a ~6 weeks after applying to net-next). > Anyway, I'll investigate iwlwifi's Rx processing -- maybe I could find > something driver-specific that might produce this. > > Thank you for the report. > >> I did a bisect, and this commit was named the culprit. I then applied >> the reverse patch on another clone of Linux next-20191122, and it >> started working. >> >> 6570bc79c0dfff0f228b7afd2de720fb4e84d61d >> net: core: use listified Rx for GRO_NORMAL in napi_gro_receive() >> >> You can see more at the bug report I filed at [0]. >> >> [0] >> https://bugzilla.kernel.org/show_bug.cgi?id=205647 >> >> I called on others at [0] to try to reproduce this - you should not >> pull >> a patch because of a single reporter - as I could be wrong. >> >> Please let me know if you want me to give more debugging information >> or >> test any potential fixes. I am happy to help to fix this. :)
And you can also set /proc/sys/net/core/gro_normal_batch to the value of 1 and see if there are any changes. This value makes GRO stack to behave just like without the patch.
>> Kind regards, >> Nicholas Johnson > > Regards, > ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ
Regards, ᚷ ᛖ ᚢ ᚦ ᚠ ᚱ
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