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Subject: Re: [PATCH] async: Let kfree() out of the critical area of the lock
To:     dsterba@suse.cz, Yunfeng Ye <yeyunfeng@huawei.com>,
        bhelgaas@google.com, "tglx@linutronix.de" <tglx@linutronix.de>,
        Alexander Duyck <alexander.h.duyck@linux.intel.com>,
        sakari.ailus@linux.intel.com,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        David Sterba <dsterba@suse.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <216356b1-38c1-8477-c4e8-03f497dd6ac8@huawei.com>
 <f49df2d42d7e97b61a5e26ff4d89ede5fbe37a35.camel@linux.intel.com>
 <e59af8ae-bacb-2e7e-dd53-ea283960d40e@huawei.com>
 <20190926110648.GM2751@suse.cz>
From:   Bart Van Assche <bvanassche@acm.org>
Message-ID: <e339db78-413c-446a-8e07-40e6e1ad4a31@acm.org>
Date:   Thu, 26 Sep 2019 08:18:38 -0700
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On 9/26/19 4:06 AM, David Sterba wrote:
> On Thu, Sep 26, 2019 at 03:58:36PM +0800, Yunfeng Ye wrote:
>> The async_lock is big global lock, I think it's good to put kfree() outside
>> to keep the critical area as short as possible.
> 
> Agreed, kfree is not always cheap. We had patches in btrfs moving kfree
> out of critical section(s) after causing softlockups due to increased lock
> contention.

The above would be a great addition for the commit description. Anyway:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>