linux-kernel - Re: [PATCH] block: respect virtual boundary mask in bvecs

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Message-ID: <7c649b43-f952-cf94-93d6-44fb153acced@suse.de>
Date:   Mon, 5 Nov 2018 12:50:50 +0100
From:   Johannes Thumshirn <jthumshirn@...e.de>
To:     Ming Lei <ming.lei@...hat.com>
Cc:     Jens Axboe <axboe@...com>,
        Linux Block Layer Mailinglist <linux-block@...r.kernel.org>,
        Hannes Reinecke <hare@...e.de>,
        Linux Kernel Mailinglist <linux-kernel@...r.kernel.org>,
        Jan Kara <jack@...e.cz>, Sagi Grimberg <sagi@...mberg.me>
Subject: Re: [PATCH] block: respect virtual boundary mask in bvecs

On 05/11/2018 11:55, Ming Lei wrote:
> On Mon, Nov 05, 2018 at 11:23:01AM +0100, Johannes Thumshirn wrote:
>> With drivers like iSer we are seeing a lot of bio splitting and smaller I/Os
>> being submitted to the driver.
>>
>> The root cause of this issue that the virtual boundary mask code does not take
>> into consideration that some of the memory segments in the SG list may have
>> come from a huge memory page that is being managed in the SG list as 4K
> 
> I guess you mean something like 64K PAGE_SIZE, instead of huge page.

No I mean like a 2M page from an upper layer.

-- 
Johannes Thumshirn                                        SUSE Labs
jthumshirn@...e.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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