TM4C1294NCPDT: Post SWI from zero latency interrupt.

Tool/software:

Hello,
In my application I am going to read data via SPI from ADS8861 running at 250 kSPS.
Every 50ms I need to run a filter and downsample data to 1000SPS.

My idea was to fill up a buffer via interrupt, when the buffer is full run the downsampling filter and meanwhile switch to a second buffer and fill that up while the filtering is ongoing.

Is it possible to post a SWI from a zero latency interrupt in order to to this job?
As I understand if an interrupt is zero latency it is not under RTOS control, can this be a problem?

Thank you for your help

Paolo Mattachini