Commit b94078e6 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Linus Torvalds

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.

[ idr.c needs xarray.h]
Link: default avatarMatthew Wilcox <>
Reviewed-by: default avatarAndrew Morton <>
Cc: Rasmus Villemoes <>
Cc: Daniel Vetter <>
Cc: Tejun Heo <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent ca1250bb
......@@ -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 @@ int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
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 @@ int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end,
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);
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