Messages in this thread | | | Date | Mon, 19 Feb 2024 10:46:31 +0000 | From | Simon Horman <> | Subject | Re: [PATCH net-next v2] net: sysfs: Do not create sysfs for non BQL device |
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On Fri, Feb 16, 2024 at 07:45:37PM +0100, Eric Dumazet wrote: > On Fri, Feb 16, 2024 at 7:41 PM Florian Fainelli <f.fainelli@gmail.com> wrote: > > > > On 2/16/24 09:29, Stephen Hemminger wrote: > > > On Fri, 16 Feb 2024 01:41:52 -0800 > > > Breno Leitao <leitao@debian.org> wrote: > > > > > >> +static bool netdev_uses_bql(const struct net_device *dev) > > >> +{ > > >> + if (dev->features & NETIF_F_LLTX || > > >> + dev->priv_flags & IFF_NO_QUEUE) > > >> + return false; > > >> + > > >> + return IS_ENABLED(CONFIG_BQL); > > >> +} > > > > > > Various compilers will warn about missing parens in that expression. > > > It is valid but mixing & and || can be bug trap. > > > > > > if ((dev->features & NETIF_F_LLTX) || (dev->priv_flags & IFF_NO_QUEUE)) > > > return false; > > > > > > Not all drivers will be using bql, it requires driver to have that code. > > > So really it means driver could be using BQL. > > > Not sure if there is a way to find out if driver has the required BQL bits. > > > > There is not a feature flag to be keying off if that is what you are > > after, you would need to audit the drivers and see whether they make > > calls to netdev_tx_sent_queue(), netdev_tx_reset_queue(), > > netdev_tx_completed_queue(). > > > > I suppose you might be able to programmatically extract that information > > by looking at whether a given driver object file has a reference to > > dql_{reset,avail,completed} or do that at the source level, whichever is > > easier. > > Note that the suggested patch does not change current functionality. > > Traditionally, we had sysfs entries fpr BQL for all netdev, regardless of them > using BQL or not. > > The patch seems to be a good first step. > > If anyone wants to refine it further, this is great, but I suspect > very few users will benefit from > having less sysfs entries for real/physical devices.... >
From my point of view the main advantage in not having these entries would be that it is really a bit confusing for them to be there that don't use BQL. But I agree, that is (also) likely to benefit few users.
In any case, I agree this is a good first step.
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