What is "context"? In the documentation I saw different mention of context like: interrupt, nmi, softirq, tasklet, timer, process, kernel, user, ethernet networking etc. >From the CPU standpoint, we have different CPL (or ring 0 and 3). And at every ring level, we have interrupt vs non-interrupt mode of operation. Basically it is just interrupt vs non-interrupt context. So this means that kernel/softirq/tasklet are all the same context - non-interrupt mode running at ring0, but seemingly everyone treat it as different context - is that so? If so, then what differentiate tasklet vs other context, from hardware perspective? Based on this I cannot understand this: Eg, in Documentation/mutex-design.txt: "The stricter mutex API means you cannot use mutexes the same way you can use semaphores: e.g. they cannot be used from an interrupt context, nor can they be unlocked from a different context that which acquired it." ===> last time is not understandable. What is the meaning of this "context"? Why? What problem can it give rise to if not followed? My understanding is (from above) is that there are only two context - interrupt vs non-interrupt mode. So first sentence already eliminate the possibility of interrupt context, leaving only non-interrupt mode. But the line "different context that which acquired it" implied different context exists? -- Regards, Peter Teoh -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
