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Date:   Thu, 20 Oct 2022 13:26:16 +0100
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Subject: Re: [RFC for-next v2 3/4] block/bio: add pcpu caching for non-polling
 bio_put
To:     Christoph Hellwig <hch@infradead.org>
Cc:     Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        io-uring@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
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 <Y1EHb36rQgqwbsXD@infradead.org>
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From:   Pavel Begunkov <asml.silence@gmail.com>
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On 10/20/22 09:31, Christoph Hellwig wrote:
>> +	unsigned long flags;
>>   
>>   	cache = per_cpu_ptr(bio->bi_pool->cache, get_cpu());
>>   	bio_uninit(bio);
>> @@ -737,12 +776,15 @@ static inline void bio_put_percpu_cache(struct bio *bio)
>>   		cache->free_list = bio;
>>   		cache->nr++;
>>   	} else {
>> -		put_cpu();
>> -		bio_free(bio);
>> -		return;
>> +		local_irq_save(flags);
>> +		bio->bi_next = cache->free_list_irq;
>> +		cache->free_list_irq = bio;
>> +		cache->nr_irq++;
>> +		local_irq_restore(flags);
>>   	}
> 
> Ok, I guess with that my previous comments don't make quite
> as much sense any more.  I think youcan keep flags local in

Yeah, a little bit of oracle coding

> the branch here, though.

Not like it makes any difference but can move it

-- 
Pavel Begunkov