linux-kernel - Re: [PATCH] mm: reduce tlb flush range when changing vma protection

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Message-ID: <47b0425d-811e-aeae-3d3d-6b7e730540de@loongson.cn>
Date:   Wed, 9 Mar 2022 13:13:59 +0800
From:   maobibo <maobibo@...ngson.cn>
To:     Nadav Amit <nadav.amit@...il.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Linux-MM <linux-mm@...ck.org>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] mm: reduce tlb flush range when changing vma protection

yeap, your patch is general and better than mine, it can solve the issue.
please drop my patch.

regards
bibo, mao

On 03/09/2022 12:14 PM, Nadav Amit wrote:
> 
> 
>> On Mar 8, 2022, at 6:57 PM, Bibo Mao <maobibo@...ngson.cn> wrote:
>>
>> numa worker will periodically change vma prot with PROT_NONE, by
>> default it will scan 256M vma memory size with pmd stepping size.
>> If there are fewer pages changed with PROT_NONE, tlb flush is called
>> with pmd size. This patch will calculate flush range for those
>> pages with pte prot changed, it will reduce size for tlb flush.
>>
>> Signed-off-by: Bibo Mao <maobibo@...ngson.cn>
> 
> Hi Bibo,
> 
> I finally managed to make v3 of a patchiest, which I think does
> something similar to what you are looking for (without introducing
> yet another TLB batching mechanism).
> 
> Have a look at [1] and let me know if that would satisfy you.
> 
> 
> [1] https://lore.kernel.org/linux-mm/20220309041043.302261-4-namit@vmware.com/T/#u
>