Hello! May i ask some questions of the current state of softirq processing with PREEMPT_RT. In 4.19.173-rt72 timer softirq processing is split into its own thread ktimersoftd. patches\0124-softirq-split-timer-softirqs-out-of-ksoftirqd.patch This timer split existed for years. Since 5.0.19 its gone because of a softirq rework. 6f6ba7715a91877cf5fd2b357db3799baa331d9b I only found this info about it: https://lwn.net/ml/linux-rt-users/CAFzL-7tzwnBEnt_q2f0BPSAO3To_Zaxt4bLtfzKVOiyJTua45g@xxxxxxxxxxxxxx/ https://lwn.net/Articles/789761/ Can anyone give me a more detailed / simpler explanation why it was removed? Others are also effected by this change: https://www.spinics.net/lists/linux-rt-users/msg23051.html https://bugzilla.redhat.com/show_bug.cgi?id=1303733 For our application it was necessary to increase the processing priority of timer tasks by setting the ktimersoftd priority higher than the ksoftirqd. Now this is not possible anymore. Does a method to increase timer task processing over the other not so important ksoftirqd workloads still exist? Another way to gain a lot more control over different system components would be this patch, which split every softirq in its own kthread. https://lore.kernel.org/patchwork/patch/513177/ This patch is very outdated and I am not able to port it. Do I miss something? Is there any way to set different priorities for each softirq as of 5.4.y-rt? e.g. to reduce the priority of NET_RX_SOFTIRQ / BLOCK_SOFTIRQ Control over NET_RX_SOFTIRQ would help in network flood situations. Thanks in advance!
