linux-kernel - Re: [RFC for-next v2 3/4] block/bio: add pcpu caching for non-polling bio

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2b29a76c-682e-208f-8a0f-d693b6823482@gmail.com>
Date:   Thu, 20 Oct 2022 13:26:16 +0100
From:   Pavel Begunkov <asml.silence@...il.com>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Jens Axboe <axboe@...nel.dk>, linux-block@...r.kernel.org,
        io-uring@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-fsdevel@...r.kernel.org
Subject: Re: [RFC for-next v2 3/4] block/bio: add pcpu caching for non-polling
 bio_put

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