From 23c887522e912ca494950796a95df8dd210f4b01 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Sat, 10 Feb 2007 01:45:05 -0800 Subject: [PATCH] Relay: add CPU hotplug support Mathieu originally needed to add this for tracing Xen, but it's something that's needed for any application that can be tracing while cpus are added. unplug isn't supported by this patch. The thought was that at minumum a new buffer needs to be added when a cpu comes up, but it wasn't worth the effort to remove buffers on cpu down since they'd be freed soon anyway when the channel was closed. [zanussi@us.ibm.com: avoid lock_cpu_hotplug deadlock] Signed-off-by: Mathieu Desnoyers Cc: Tom Zanussi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/relay.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/relay.h b/include/linux/relay.h index c6a48bfc8b1..759a0f97bec 100644 --- a/include/linux/relay.h +++ b/include/linux/relay.h @@ -24,7 +24,7 @@ /* * Tracks changes to rchan/rchan_buf structs */ -#define RELAYFS_CHANNEL_VERSION 6 +#define RELAYFS_CHANNEL_VERSION 7 /* * Per-cpu relay channel buffer @@ -64,6 +64,10 @@ struct rchan void *private_data; /* for user-defined data */ size_t last_toobig; /* tried to log event > subbuf size */ struct rchan_buf *buf[NR_CPUS]; /* per-cpu channel buffers */ + int is_global; /* One global buffer ? */ + struct list_head list; /* for channel list */ + struct dentry *parent; /* parent dentry passed to open */ + char base_filename[NAME_MAX]; /* saved base filename */ }; /* @@ -162,7 +166,8 @@ struct rchan *relay_open(const char *base_filename, struct dentry *parent, size_t subbuf_size, size_t n_subbufs, - struct rchan_callbacks *cb); + struct rchan_callbacks *cb, + void *private_data); extern void relay_close(struct rchan *chan); extern void relay_flush(struct rchan *chan); extern void relay_subbufs_consumed(struct rchan *chan, -- cgit v1.2.3-18-g5258