From: Willy Tarreau <w@1wt.eu>
To: Andy Lutomirski <luto@kernel.org>
Cc: dev@dpdk.org, Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [dpdk-dev] Please stop using iopl() in DPDK
Date: Fri, 25 Oct 2019 17:03:45 +0200 [thread overview]
Message-ID: <20191025150345.GE23687@1wt.eu> (raw)
In-Reply-To: <CALCETrXtKBtMx3gf2BysCeYEzDFN_wjiKCGh_onCdA=7TbBxZw@mail.gmail.com>
On Fri, Oct 25, 2019 at 07:45:47AM -0700, Andy Lutomirski wrote:
> But, for uses like DPDK, /sys/.../resource0 seems like a *far* better
> API, since it actually uses the kernel's concept of which io range
> corresponds to which device instead of hoping that the mappings don't
> change out from under user code. And it has the added benefit that
> it's restricted to a single device.
For certain such uses with real device management, very likely yes.
It's just that in a number of programs using hard-coded ports to
access stupid devices with no driver (and often even no name), such
an approach could be overkill, and these are typically the annoyingly
itchy ones which could require your config entry to remain enabled.
I'll add to my todo list to have a look at this as time permits.
Cheers,
Willy
WARNING: multiple messages have this Message-ID (diff)
From: Willy Tarreau <w@1wt.eu>
To: Andy Lutomirski <luto@kernel.org>
Cc: dev@dpdk.org, Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: Please stop using iopl() in DPDK
Date: Fri, 25 Oct 2019 17:03:45 +0200 [thread overview]
Message-ID: <20191025150345.GE23687@1wt.eu> (raw)
In-Reply-To: <CALCETrXtKBtMx3gf2BysCeYEzDFN_wjiKCGh_onCdA=7TbBxZw@mail.gmail.com>
On Fri, Oct 25, 2019 at 07:45:47AM -0700, Andy Lutomirski wrote:
> But, for uses like DPDK, /sys/.../resource0 seems like a *far* better
> API, since it actually uses the kernel's concept of which io range
> corresponds to which device instead of hoping that the mappings don't
> change out from under user code. And it has the added benefit that
> it's restricted to a single device.
For certain such uses with real device management, very likely yes.
It's just that in a number of programs using hard-coded ports to
access stupid devices with no driver (and often even no name), such
an approach could be overkill, and these are typically the annoyingly
itchy ones which could require your config entry to remain enabled.
I'll add to my todo list to have a look at this as time permits.
Cheers,
Willy
next prev parent reply other threads:[~2019-10-27 22:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-25 4:45 [dpdk-dev] Please stop using iopl() in DPDK Andy Lutomirski
2019-10-25 4:45 ` Andy Lutomirski
2019-10-25 6:42 ` [dpdk-dev] " Willy Tarreau
2019-10-25 6:42 ` Willy Tarreau
2019-10-25 14:45 ` [dpdk-dev] " Andy Lutomirski
2019-10-25 14:45 ` Andy Lutomirski
2019-10-25 15:03 ` Willy Tarreau [this message]
2019-10-25 15:03 ` Willy Tarreau
2019-10-27 23:44 ` [dpdk-dev] " Maciej W. Rozycki
2019-10-27 23:44 ` Maciej W. Rozycki
2019-10-28 16:42 ` [dpdk-dev] " Stephen Hemminger
2019-10-28 18:00 ` Andy Lutomirski
2019-10-28 20:13 ` Willy Tarreau
2019-10-25 7:22 ` David Marchand
2019-10-25 16:13 ` Stephen Hemminger
2019-10-25 20:43 ` Thomas Gleixner
2019-10-26 0:27 ` Andy Lutomirski
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