Hello, Kazimierz. On Wed, Feb 24, 2016 at 12:53:13PM +0100, Kazimierz Krosman wrote: > 1. kmsg device does not require maintenance by reader process side. > Multiple writers can write to a device and new records overwrite logs saved earlier. > When system crashes logs can be restored with pstore mechanism. I'm not sure this is the right layer to implement generic logging facility. > 2. Using kmsg can cause lower CPU utilisation in the real-word use case than > userspace logging mechanisms. > We created 2 tests: (1) 100 writer processes write to created kmsg buffer and > (2) 100 writers write to socket (stream)- there is one reader to protect > socket buffer against overflow. Tests show that cpu utilisation in case of first > test is about 2.3 times lower (39.1%) than it is in second case (87.7%) (measured > with top program; tests code is attached below). Tested on Odroid XU4. This sounds like a generic IPC problem than anything else. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
