Day: July 19, 2017

The Curious Case of Thread Group Identifiers

At MemSQL, we are out to build awesome software and we’re always trying to solve hard problems. A few days ago, I uncovered a cool Linux mystery with some colleagues and fixed it. We thought sharing that experience might benefit others. The scene of the crime While developing an internal tool to get stack traces, we decided to use the SYS_tgkill Linux system call to send signals to specific threads. The tgkill syscall sends a signal to a specific thread based on its “thread group”...