Re: [PATCH 4/6] Xarray: skip unneeded xas_store() and xas_clear_mark() in __xa_alloc()

From: Kemeng Shi
Date: Sun Nov 03 2024 - 20:56:30 EST




on 11/2/2024 12:02 AM, Matthew Wilcox wrote:
> On Fri, Nov 01, 2024 at 11:50:26PM +0800, Kemeng Shi wrote:
>> If xas_find_marked() failed, there is no need to call xas_store() and
>> xas_clear_mark(). Just call xas_store() and xas_clear_mark() if
>> xas_find_marked() succeed.
>
> No. The point of the xas interfaces is that they turn into no-ops once
> an error has occurred.
Yes, xas interfaces can tolerate error. The question is do we really need to
call xas_store(...) here if we already know there is no room to store new entry.
But no insistant on this as it's not a big deal anyway.

Will drop this on next version if you still disklike this.
Thanks.

>
>> - else
>> + else {
>> *id = xas.xa_index;
>> - xas_store(&xas, entry);
>> - xas_clear_mark(&xas, XA_FREE_MARK);
>> + xas_store(&xas, entry);
>> + xas_clear_mark(&xas, XA_FREE_MARK);
>> + }
>> } while (__xas_nomem(&xas, gfp));
>>
>> return xas_error(&xas);
>> --
>> 2.30.0
>>
>