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. [akpm@xxxxxxxxxxxxxxxxxxxx: idr.c needs xarray.h] 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 | 10 +++++----- 1 file changed, 5 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 @@ -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 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); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
