Re: [PATCH RESEND 2/2] mm/zswap: refoctor the get/put routines

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Oct 25, 2013 at 6:20 PM, Minchan Kim <minchan@xxxxxxxxxx> wrote:
> On Thu, Oct 24, 2013 at 05:53:32PM +0800, Weijie Yang wrote:
>> The refcount routine was not fit the kernel get/put semantic exactly,
>> There were too many judgement statements on refcount and it could be minus.
>>
>> This patch does the following:
>>
>> - move refcount judgement to zswap_entry_put() to hide resource free function.
>>
>> - add a new function zswap_entry_find_get(), so that callers can use easily
>> in the following pattern:
>>
>>    zswap_entry_find_get
>>    .../* do something */
>>    zswap_entry_put
>>
>> - to eliminate compile error, move some functions declaration
>>
>> This patch is based on Minchan Kim <minchan@xxxxxxxxxx> 's idea and suggestion.
>>
>> Signed-off-by: Weijie Yang <weijie.yang@xxxxxxxxxxx>
>> Cc: Seth Jennings <sjennings@xxxxxxxxxxxxxx>
>> Cc: Minchan Kim <minchan@xxxxxxxxxx>
>> Cc: Bob Liu <bob.liu@xxxxxxxxxx>
>
>
> I remember Bob had a idea to remove a look up and I think it's doable.
> Anyway, I don't mind you send it with fix or not.

Thanks for review.

Bob's idea is:
"Then how about  use if (!RB_EMPTY_NODE(&entry->rbnode))  to
 replace rbtree searching?"

I'm afraid not. Because entry could be freed in previous zswap_entry_put,
we cann't reference entry or we would touch a free-and-use issue.

> Thanks for handling this, Weijie!
>
> Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
>
> --
> Kind regards,
> Minchan Kim

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux]     [Linux OMAP]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]