The patch titled
Subject: lib/idr.c: remove simple_ida_lock
has been added to the -mm tree. Its filename is
ida-remove-simple_ida_lock.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ida-remove-simple_ida_lock.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ida-remove-simple_ida_lock.patch
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there every 3-4 working days
------------------------------------------------------
From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Subject: 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.
Link: http://lkml.kernel.org/r/20180331125332.GF13332@xxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/idr.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff -puN lib/idr.c~ida-remove-simple_ida_lock lib/idr.c
--- a/lib/idr.c~ida-remove-simple_ida_lock
+++ a/lib/idr.c
@@ -6,7 +6,6 @@
#include <linux/spinlock.h>
DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap);
-static DEFINE_SPINLOCK(simple_ida_lock);
/**
* idr_alloc_u32() - Allocate an ID.
@@ -581,7 +580,7 @@ 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 +590,7 @@ 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 +614,8 @@ void ida_simple_remove(struct ida *ida,
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);
_
Patches currently in -mm which might be from mawilcox@xxxxxxxxxxxxx are
fix-null-pointer-in-page_cache_tree_insert.patch
slab-__gfp_zero-is-incompatible-with-a-constructor.patch
ida-remove-simple_ida_lock.patch
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