Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=d973a77bdb3ade9240173b6ed6e003a319499211
Commit: d973a77bdb3ade9240173b6ed6e003a319499211
Parent: 1d1497e1f9ffe2f7198c916abd112226a7a503f2
Author: Jeff Dike <[EMAIL PROTECTED]>
AuthorDate: Sun May 6 14:51:27 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Mon May 7 12:13:02 2007 -0700
uml: irq locking commentary
Locking commentary.
Signed-off-by: Jeff Dike <[EMAIL PROTECTED]>
Cc: Paolo 'Blaisorblade' Giarrusso <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
arch/um/kernel/irq.c | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index a1e8c46..8f2ed36 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -78,6 +78,14 @@ skip:
return 0;
}
+/*
+ * This list is accessed under irq_lock, except in sigio_handler,
+ * where it is safe from being modified. IRQ handlers won't change it -
+ * if an IRQ source has vanished, it will be freed by free_irqs just
+ * before returning from sigio_handler. That will process a separate
+ * list of irqs to free, with its own locking, coming back here to
+ * remove list elements, taking the irq_lock to do so.
+ */
static struct irq_fd *active_fds = NULL;
static struct irq_fd **last_irq_ptr = &active_fds;
@@ -243,6 +251,7 @@ void free_irq_by_fd(int fd)
free_irq_by_cb(same_fd, &fd);
}
+/* Must be called with irq_lock held */
static struct irq_fd *find_irq_by_fd(int fd, int irqnum, int *index_out)
{
struct irq_fd *irq;
@@ -308,6 +317,12 @@ void deactivate_fd(int fd, int irqnum)
ignore_sigio_fd(fd);
}
+/*
+ * Called just before shutdown in order to provide a clean exec
+ * environment in case the system is rebooting. No locking because
+ * that would cause a pointless shutdown hang if something hadn't
+ * released the lock.
+ */
int deactivate_all_fds(void)
{
struct irq_fd *irq;
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
