On Mon, Dec 22, 2014 at 01:51:27AM +0000, Liang, Cunming wrote: > ... > > I'm conflicted on this one. However, I think far more applications would be > > broken > > to start having to use thread_id in place of an lcore_id than would be > > broken > > by having the lcore_id no longer actually correspond to a core. > > I'm actually struggling to come up with a large number of scenarios where > > it's > > important to an app to determine the cpu it's running on, compared to the > > large > > number of cases where you need to have a data-structure per thread. In DPDK > > libs > > alone, you see this assumption that lcore_id == thread_id a large number of > > times. > > > > Despite the slight logical inconsistency, I think it's better to avoid > > introducing > > a thread-id and continue having lcore_id representing a unique thread. > > > > /Bruce > > Ok, I understand it. > I list the implicit meaning if using lcore_id representing the unique thread. > 1). When lcore_id less than RTE_MAX_LCORE, it still represents the logical > core id. > 2). When lcore_id large equal than RTE_MAX_LCORE, it represents an unique id > for thread. > 3). Most of APIs(except rte_lcore_id()) in rte_lcore.h suggest to be used > only in CASE 1) > 4). rte_lcore_id() can be used in CASE 2), but the return value no matter > represent a logical core id. > > If most of us feel it's acceptable, I'll prepare for the RFC v2 base on this > conclusion. > > /Cunming
Sorry, I don't like that suggestion either, as having lcore_id values greater than RTE_MAX_LCORE is terrible, as how will people know how to dimension arrays to be indexes by lcore id? Given the choice, if we are not going to just use lcore_id as a generic thread id, which is always between 0 and RTE_MAX_LCORE we can look to define a new thread_id variable to hold that. However, it should have a bounded range. >From an ease-of-porting perspective, I still think that the simplest option is >to use the existing lcore_id and accept the fact that it's now a thread id rather than an actual physical lcore. Question is, is would that cause us lots of issues in the future? /Bruce