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/include/net/ipconfig.h

/*
 *  Copyright (C) 1997 Martin Mares
 *
 *  Automatic IP Layer Configuration
 */

/* The following are initdata: */

extern int ic_proto_enabled;	/* Protocols enabled (see IC_xxx) */
extern int ic_set_manually;	/* IPconfig parameters set manually */

extern __be32 ic_myaddr;		/* My IP address */
extern __be32 ic_gateway;		/* Gateway IP address */

extern __be32 ic_servaddr;		/* Boot server IP address */

extern __be32 root_server_addr;	/* Address of NFS server */
extern u8 root_server_path[];	/* Path to mount as root */


/* bits in ic_proto_{enabled,used} */
#define IC_PROTO	0xFF	/* Protocols mask: */
#define IC_BOOTP	0x01	/*   BOOTP (or DHCP, see below) */
#define IC_RARP		0x02	/*   RARP */
#define IC_USE_DHCP    0x100	/* If on, use DHCP instead of BOOTP */