On 2024/7/11 0:41, Bart Van Assche wrote:
On 7/9/24 11:56 PM, Yang Yang wrote:
+ spin_lock_irqsave(&map->swap_lock, flags);
Please use guard(spinlock_irqsave) in new code instead of spin_lock_irqsave() + goto out_unlock
+ spin_unlock_irqrestore().
That will make this function significantly easier to read and to
maintain.
Got it.
+
+ if (!map->cleared) {
+ if (depth > 0) {
+ word_mask = (~0UL) >> (BITS_PER_LONG - depth);
+ /*
+ * The current behavior is to always retry after moving
+ * ->cleared to word, and we change it to retry in case
+ * of any free bits. To avoid dead loop, we need to take
What is a "dead loop"? Did you perhaps want to write "infinite loop"?
Yeah. I suppose so.
+ * wrap & alloc_hint into account. Without this, a soft
+ * lockup was detected in our test environment.
Source code comments should not refer to "our test environment". Code
that is intended for upstream inclusion should work for all setups.
Got it.
+ */
+ if (!wrap && alloc_hint)
+ word_mask &= ~((1UL << alloc_hint) - 1);
Above I see an open-coded __clear_bit() operation. Has it been
considered to use __clear_bit() instead of open-coding it?
It is meant to reset multiple bits to zero, but __clear_bit() is only
capable of resetting one bit to zero.
Thanks.
Thanks,
Bart.
