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
| ||
|
Message-ID: <20230524085507.3f38c758@kernel.org> Date: Wed, 24 May 2023 08:55:07 -0700 From: Jakub Kicinski <kuba@...nel.org> To: Sebastian Andrzej Siewior <bigeasy@...utronix.de> Cc: netdev@...r.kernel.org, Eric Dumazet <edumazet@...gle.com>, Kurt Kanzenbach <kurt.kanzenbach@...utronix.de>, Paolo Abeni <pabeni@...hat.com>, Thomas Gleixner <tglx@...utronix.de> Subject: Re: [RFC PATCH 1/2] net: Add sysfs files for threaded NAPI. On Wed, 24 May 2023 13:12:58 +0200 Sebastian Andrzej Siewior wrote: > I've been looking into threaded NAPI. One awkward thing to do is > to figure out the thread names, pids in order to adjust the thread > priorities and SMP affinity. > On PREEMPT_RT the NAPI thread is treated (by the user) the same way as > the threaded interrupt which means a dedicate CPU affinity for the > thread and a higher task priority to be favoured over other tasks on the > CPU. Otherwise the NAPI thread can be preempted by other threads leading > to delays in packet delivery. > Having to run ps/ grep is awkward to get the PID right. It is not easy > to match the interrupt since there is no obvious relation between the > IRQ and the NAPI thread. > NAPI threads are enabled often to mitigate the problems caused by a > "pending" ksoftirqd (which has been mitigated recently by doing softiqrs > regardless of ksoftirqd status). There is still the part that the NAPI > thread does not use softnet_data::poll_list. This needs to go to the netdev netlink family, not sysfs. There's much more information about NAPI to expose and sysfs will quickly start showing its limitations.
Powered by blists - more mailing lists