linux-kernel - Re: [PATCH v7 10/24] x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <af4ebcec-8a65-44fb-f00e-c7bbffe480e2@arm.com>
Date:   Thu, 14 Dec 2023 11:36:50 +0000
From:   James Morse <james.morse@....com>
To:     Reinette Chatre <reinette.chatre@...el.com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Cc:     Fenghua Yu <fenghua.yu@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        H Peter Anvin <hpa@...or.com>,
        Babu Moger <Babu.Moger@....com>,
        shameerali.kolothum.thodi@...wei.com,
        D Scott Phillips OS <scott@...amperecomputing.com>,
        carl@...amperecomputing.com, lcherian@...vell.com,
        bobo.shaobowang@...wei.com, tan.shaopeng@...itsu.com,
        baolin.wang@...ux.alibaba.com, Jamie Iles <quic_jiles@...cinc.com>,
        Xin Hao <xhao@...ux.alibaba.com>, peternewman@...gle.com,
        dfustini@...libre.com, amitsinght@...vell.com
Subject: Re: [PATCH v7 10/24] x86/resctrl: Allocate the cleanest CLOSID by
 searching closid_num_dirty_rmid

On 09/11/2023 17:46, Reinette Chatre wrote:
> Hi James,
> 
> On 10/25/2023 11:03 AM, James Morse wrote:
>> MPAM's PMG bits extend its PARTID space, meaning the same PMG value can be
>> used for different control groups.
>>
>> This means once a CLOSID is allocated, all its monitoring ids may still be
>> dirty, and held in limbo.
>>
>> Instead of allocating the first free CLOSID, on architectures where
>> CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is enabled, search
>> closid_num_dirty_rmid[] to find the cleanest CLOSID.
>>
>> The CLOSID found is returned to closid_alloc() for the free list
>> to be updated.
>>
>> Tested-by: Shaopeng Tan <tan.shaopeng@...itsu.com>
>> Tested-by: Peter Newman <peternewman@...gle.com>
>> Reviewed-by: Shaopeng Tan <tan.shaopeng@...itsu.com>
>> Reviewed-by: Reinette Chatre <reinette.chatre@...el.com>
>> Signed-off-by: James Morse <james.morse@....com>
>> ---
>> Changes since v4:
>>  * Dropped stale section from comment
>>
>> Changes since v5:
>>  * Renamed some variables.
>>
>> No changes since v6
> 
> I use these patch changelogs to determine if I need to look at a
> patch for which I already provided a review tag. At first this
> patch appears to not deserve a second glance because I already provided a
> review tag and the above states "No changes since v6". Unfortunately
> this is false. I counted four changes. Now I cannot trust these
> "No changes since v6" and I need to dig out v6 to diff patches I already
> reviewed to determine if I need to look at them again. False patch
> changelogs make a patch series harder to review.

Sorry, looks like I applied the changes suggested by Babu, but didn't update this bit of
text that doesn't get committed. I added this 'No changes' text to any patch that didn't
have any entries.

You should be able to rely on people dropping Reviewed-by tags if there are substantial
changes. This is the normal threshold for re-reviewing a patch.



James