Since the consensus seems to be to eliminate semaphores where possible,
we shouldn't be educating people about how to use them as locks. Use
mutexes instead. Semaphores should be described in a separate document
if we end up keeping them.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Add a chapter about trylock functions.
http://bugzilla.kernel.org/show_bug.cgi?id=9011
Signed-off-by: Matti Linnanvuori <mattilinnanvuori@yahoo.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (removed down_trylock)
I converted some of the document to reflect mutex usage instead of
semaphore usage. Since we shouldin't be promoting semaphore usage when
it's on it's way out..
Signed-off-by: Daniel Walker <dwalker@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change a headline to reflect that there are three main types of kernel
locking, not two.
Signed-off-by: Linus Nilsson <lajnold@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andi Kleen pointed out to me that the kernel locking cheat sheet
table entries are unreadable.
Make table entries smaller so that pdf and ps output is readable
(columns were being overwritten and garbled) by using abbreviations.
This allows the tables to fit on one page cleanly.
Add a Legend for the abbreviations:
SLIS: spin_lock_irqsave
SLI: spin_lock_irq
SL: spin_lock
SLBH: spin_lock_bh
DI: down_interruptible
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Matthew Wilcox