linux-kernel - Re: [PATCH] async: Let kfree() out of the critical area of the lock

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Message-ID: <cadede43-776e-449d-c6e5-c7f9c2c1acf2@huawei.com>
Date:   Fri, 27 Sep 2019 09:00:41 +0800
From:   Yunfeng Ye <yeyunfeng@...wei.com>
To:     Bart Van Assche <bvanassche@....org>, <dsterba@...e.cz>,
        <bhelgaas@...gle.com>, "tglx@...utronix.de" <tglx@...utronix.de>,
        "Alexander Duyck" <alexander.h.duyck@...ux.intel.com>,
        <sakari.ailus@...ux.intel.com>,
        "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
        David Sterba <dsterba@...e.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] async: Let kfree() out of the critical area of the lock



On 2019/9/26 23:18, Bart Van Assche wrote:
> 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:
> 
ok, I will update the description, thanks.

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