tracing: Fix hwlat kthread migration

The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.

The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.

Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

path: root/lookup.h

/*
 * netsniff-ng - the packet sniffing beast
 * Copyright 2009, 2010 Daniel Borkmann.
 * Copyright 2014 Tobias Klauser
 * Subject to the GPL, version 2.
 */

#ifndef LOOKUP_H
#define LOOKUP_H

enum ports {
	PORTS_UDP,
	PORTS_TCP,
	PORTS_ETHER,
	PORTS_MAX,
};

extern void lookup_init_ports(enum ports which);
extern void lookup_cleanup_ports(enum ports which);

extern char *lookup_port_udp(unsigned int id);
extern char *lookup_port_tcp(unsigned int id);
extern char *lookup_ether_type(unsigned int id);

#endif /* LOOKUP_H */