netdev - Re: [Intel-wired-lan] [PATCH] igb: Make driver init async

Open Source and information security mailing list archives

Message-ID: <CAKgT0UdU3+bdnpHF3wGu+_zFCokJmQeFWKYrc+v+-MQPuTW37g@mail.gmail.com>
Date:   Mon, 21 Jan 2019 14:50:08 -0800
From:   Alexander Duyck <alexander.duyck@...il.com>
To:     Feng Tang <feng.tang@...el.com>
Cc:     Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        "David S . Miller" <davem@...emloft.net>,
        intel-wired-lan <intel-wired-lan@...ts.osuosl.org>,
        Netdev <netdev@...r.kernel.org>
Subject: Re: [Intel-wired-lan] [PATCH] igb: Make driver init async

On Mon, Jan 21, 2019 at 12:36 AM Feng Tang <feng.tang@...el.com> wrote:
>
> When optimizing boot time for a platform with igb module, we found the
> igb driver probe will take about 45 ms, make the probe asynchronous
> will save quite some time as the init runs in parallel with other
> asynchronous drivers.
>
> In theory, this could be applied to some other drivers like igc or
> e1000, but we don't have HW to verify that.
>
> Signed-off-by: Feng Tang <feng.tang@...el.com>

I really don't like this patch. This seems like you are tuning for a
specific platform or system setup by making changes to the driver. Is
there any reason why you couldn't just pass the module parameter
"igb.async_probe" to accomplish the same thing? I suspect most people
won't care that much about the 45ms boot time difference, and if we
were to make this sort of change it should probably be more
generically applied to either PCI devices or network devices instead
of doing this one driver at a time.

> ---
>  drivers/net/ethernet/intel/igb/igb_main.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index 7137e7f..d477253 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -229,6 +229,7 @@ static struct pci_driver igb_driver = {
>         .id_table = igb_pci_tbl,
>         .probe    = igb_probe,
>         .remove   = igb_remove,
> +       .driver.probe_type = PROBE_PREFER_ASYNCHRONOUS,
>  #ifdef CONFIG_PM
>         .driver.pm = &igb_pm_ops,
>  #endif
> --
> 2.7.4
>
> _______________________________________________
> Intel-wired-lan mailing list
> Intel-wired-lan@...osl.org
> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives