lib/idr.c: remove simple_ida_lock

Improve the scalability of the IDA by using the per-IDA xa_lock rather
than the global simple_ida_lock.  IDAs are not typically used in
performance-sensitive locations, but since we have this lock anyway, we
can use it.  It is also a step towards converting the IDA from the radix
tree to the XArray.

[akpm@linux-foundation.org: idr.c needs xarray.h]
Link: http://lkml.kernel.org/r/20180331125332.GF13332@bombadil.infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2018-06-07 17:10:45 -07:00 committed by Linus Torvalds
parent ca1250bbd4
commit b94078e695

View File

@ -4,9 +4,9 @@
#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/xarray.h>
DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap);
static DEFINE_SPINLOCK(simple_ida_lock);
/**
* idr_alloc_u32() - Allocate an ID.
@ -581,7 +581,7 @@ again:
if (!ida_pre_get(ida, gfp_mask))
return -ENOMEM;
spin_lock_irqsave(&simple_ida_lock, flags);
xa_lock_irqsave(&ida->ida_rt, flags);
ret = ida_get_new_above(ida, start, &id);
if (!ret) {
if (id > max) {
@ -591,7 +591,7 @@ again:
ret = id;
}
}
spin_unlock_irqrestore(&simple_ida_lock, flags);
xa_unlock_irqrestore(&ida->ida_rt, flags);
if (unlikely(ret == -EAGAIN))
goto again;
@ -615,8 +615,8 @@ void ida_simple_remove(struct ida *ida, unsigned int id)
unsigned long flags;
BUG_ON((int)id < 0);
spin_lock_irqsave(&simple_ida_lock, flags);
xa_lock_irqsave(&ida->ida_rt, flags);
ida_remove(ida, id);
spin_unlock_irqrestore(&simple_ida_lock, flags);
xa_unlock_irqrestore(&ida->ida_rt, flags);
}
EXPORT_SYMBOL(ida_simple_remove);