On 01/07/2019 11:14 AM, Matthew Wilcox wrote: > On Mon, Jan 07, 2019 at 11:07:47AM -0500, Waiman Long wrote: >>> Why are you caching the _output_ of calling sprintf(), rather than caching the >>> values of each interrupt? >>> >> It is just faster to dump the whole string buffer than redoing the >> number formatting each time when the values don't change. I can cache >> the individual sums instead if it is the preferred by most. > But it also consumes more memory. Can you gather some measurements to > find out what the performance difference is if you cache the values > instead of the strings? I allocate 11 bytes (10 digits + space) for each unsigned int IRQ value. I needs 4 bytes for the unsigned value itself. So it is a saving of 7 bytes. With 4k irqs, it will be 28k. I will run some measurements of caching the values versus saving the string later this week. Thanks, Longman
