linux-kernel - Re: [PATCH] ib/core: not to set page dirty bit if it's already set.

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Date:   Thu, 01 Jun 2017 18:33:59 -0400
From:   Doug Ledford <dledford@...hat.com>
To:     Qing Huang <qing.huang@...cle.com>, linux-rdma@...r.kernel.org,
        linux-kernel@...r.kernel.org
Cc:     sean.hefty@...el.com, artemyko@...lanox.com
Subject: Re: [PATCH] ib/core: not to set page dirty bit if it's already set.

On Thu, 2017-05-18 at 16:33 -0700, Qing Huang wrote:
> This change will optimize kernel memory deregistration operations.
> __ib_umem_release() used to call set_page_dirty_lock() against every
> writable page in its memory region. Its purpose is to keep data
> synced between CPU and DMA device when swapping happens after mem
> deregistration ops. Now we choose not to set page dirty bit if it's
> already set by kernel prior to calling __ib_umem_release(). This
> reduces memory deregistration time by half or even more when we ran
> application simulation test program.
> 
> Signed-off-by: Qing Huang <qing.huang@...cle.com>

Thanks, applied.

-- 
Doug Ledford <dledford@...hat.com>
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