Re: [dpdk-dev] [PATCH v5 09/10] eal: add EAL argument for setting thread priority
From: Dmitry Kozlyuk <hidden>
Date: 2021-03-31 21:12:59
2021-03-30 14:11 (UTC-0700), Stephen Hemminger:
On Mon, 29 Mar 2021 15:40:39 -0700 Narcisa Ana Maria Vasile [off-list ref] wrote:quoted
From: Narcisa Vasile <redacted> Allow the user to choose the thread priority through an EAL command line argument. The user can select the thread priority to be either 'normal' or 'critical': --thread-prio normal --thread-prio realtime Signed-off-by: Narcisa Vasile <redacted>The discussion internally was that this was intended to resolve issues on Windows. So it makes sense for Windows, but it is not something that we want to have on Linux. Could you make this Windows only, and add update the documentation please. I just don't want Linux users discovering it, trying it, then reporting more bugs.
Can you share more details of that discussion? Is realtime-critical needed not for busy-polling apps (which indeed cause starvation), but for interrupt-driven ones to process packets ASAP? If it's true, then maybe NetUIO can instead give priority boost to these threads when notifying them about interrupts (Omar? DmitryM?). This can be configurable via devargs. One downside is that every kernel driver has to support it, currently Mellanox bifurcated driver and NetUIO. But they will need some interrupt-related IOCTLs anyway.