Thread (6 messages) 6 messages, 4 authors, 2022-05-03

Re: [net-next PATCH] amt: Use BIT macros instead of open codes

From: Juhee Kang <hidden>
Date: 2022-05-03 11:33:56

Hello Paolo and Joe,

Thanks for the reviews!


On Tue, May 3, 2022 at 6:28 PM Taehee Yoo [off-list ref] wrote:
2022. 5. 3. 오전 2:19에 Joe Perches 이(가) 쓴 글:
 > On Mon, 2022-05-02 at 12:11 +0200, Paolo Abeni wrote:

Hi Paolo and Joe,
Thanks a lot for the reviews!

 >> On Sat, 2022-04-30 at 13:56 +0000, Juhee Kang wrote:
 >>> Replace open code related to bit operation with BIT macros, which
kernel
 >>> provided. This patch provides no functional change.
 > []
 >>> diff --git a/drivers/net/amt.c b/drivers/net/amt.c
 > []
 >>> @@ -959,7 +959,7 @@ static void amt_req_work(struct work_struct *work)
 >>>    amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
 >>>    spin_lock_bh(&amt->lock);
 >>>   out:
 >>> -  exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
 >>> +  exp = min_t(u32, (1 * BIT(amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
 >>>    mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp *
1000));
 >>>    spin_unlock_bh(&amt->lock);
 >>>   }
 >>> diff --git a/include/net/amt.h b/include/net/amt.h
 > []
 >>> @@ -354,7 +354,7 @@ struct amt_dev {
 >>>   #define AMT_MAX_GROUP            32
 >>>   #define AMT_MAX_SOURCE           128
 >>>   #define AMT_HSIZE_SHIFT          8
 >>> -#define AMT_HSIZE         (1 << AMT_HSIZE_SHIFT)
 >>> +#define AMT_HSIZE         BIT(AMT_HSIZE_SHIFT)
 >>>
 >>>   #define AMT_DISCOVERY_TIMEOUT    5000
 >>>   #define AMT_INIT_REQ_TIMEOUT     1
 >>
 >> Even if the 2 replaced statements use shift operations, they do not
 >> look like bit manipulation: the first one is an exponential timeout,
 >> the 2nd one is an (hash) size. I think using the BIT() macro here will
 >> be confusing.
 >
 > I agree.
 >
 > I also believe one of the uses of amt->req_cnt is error prone.
 >
 >      drivers/net/amt.c:946:  if (amt->req_cnt++ > AMT_MAX_REQ_COUNT) {
 >
 > Combining a test and post increment is not a great style IMO.
 > Is this really the intended behavior?

I agree that it would be better to avoid that style.
I will send a patch for that after some bugfix.

Thanks a lot,
Taehee Yoo

 >
 >


-- 

Best regards,
Juhee Kang
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