On 11/6/19 1:27 PM, Evgeniy Didin wrote: > Actually thread and process ID's are positive values. Accorting to > http://man7.org/linux/man-pages/man7/pthreads.7.html > threads are creating using "clone" syscall, so the ID generation mechanism > is similar for threads and processes. According to Linux source code > there is a function call tree, which allocates PID[TID]: > clone > |->_do_fork > |->copy_process > |->alloc_pid > |->idr_alloc_cyclic > |->idr_alloc_u32(idr, ptr, &id, max, gfp); > And in idr_alloc_u32() "id" is u32 value, which means positiveness. > Also according to: > https://elixir.bootlin.com/linux/latest/source/kernel/pid.c#L177 > PID cannot be less than 1. Sure for Linux. But negative numbers have meaning in the remote protocol: https://sourceware.org/gdb/current/onlinedocs/gdb/Packets.html#thread_002did-syntax Thanks, Pedro Alves _______________________________________________ linux-snps-arc mailing list linux-snps-arc@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-snps-arc
