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: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <f3008ba2-82c2-47e3-9153-139a9442123b@arm.com>
Date:   Mon, 27 Nov 2023 14:11:52 +0000
From:   Ryan Roberts <ryan.roberts@....com>
To:     David Hildenbrand <david@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Matthew Wilcox <willy@...radead.org>,
        Yin Fengwei <fengwei.yin@...el.com>,
        Yu Zhao <yuzhao@...gle.com>,
        Catalin Marinas <catalin.marinas@....com>,
        Anshuman Khandual <anshuman.khandual@....com>,
        Yang Shi <shy828301@...il.com>,
        "Huang, Ying" <ying.huang@...el.com>, Zi Yan <ziy@...dia.com>,
        Luis Chamberlain <mcgrof@...nel.org>,
        Itaru Kitayama <itaru.kitayama@...il.com>,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        John Hubbard <jhubbard@...dia.com>,
        David Rientjes <rientjes@...gle.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Hugh Dickins <hughd@...gle.com>,
        Kefeng Wang <wangkefeng.wang@...wei.com>
Cc:     linux-mm@...ck.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Subject: Re: [RESEND PATCH v7 09/10] selftests/mm/cow: Generalize
 do_run_with_thp() helper

On 27/11/2023 13:59, David Hildenbrand wrote:
>>>
>>>> +    pmdsize = read_pmd_pagesize();
>>>> +    if (pmdsize)
>>>> +        ksft_print_msg("[INFO] detected PMD-mapped THP size: %zu KiB\n",
>>>
>>> Maybe simply: "detected PMD size". Zes, we read it via the THP interface, but
>>> that shouldn't matter much.
>>
>> Err, just want to clarify what you are suggesting. With the current patch you
>> will see something like:
> 
> Not with this patch, but with the other ones, yes :)

Yep, we are on the same page (folio)...

> 
>>
>> [INFO] detected PMD-mapped THP size: 2048 KiB
>> [INFO] detected small-sized THP size: 64 KiB
>> [INFO] detected small-sized THP size: 128 KiB
>> ...
>> [INFO] detected small-sized THP size: 1024 KiB
>>
>>
>> Are you suggesting something like this:
>>
>> [INFO] detected PMD size: 2048 KiB
>> [INFO] detected THP size: 64 KiB
>> [INFO] detected THP size: 128 KiB
>> ...
>> [INFO] detected THP size: 2048 KiB
>>
> 
> Yes. If you'd detect that 2M is actually disabled, you could still log the PMD
> size only.

Note that in the final patch, where I test the other THP sizes, I'm not
detecting which sizes the sysadmin has enabled, I'm detecting the set of sizes
that can be enabled, then explicitly enabling the size (exclusively) when I test
it. So there is no chance of reading PMD size but not having 2M THP. Minor point
though.

> 
> So for this patch only as a preparation
> 
> [INFO] detected PMD size: 2048 KiB
> [INFO] detected THP size: 2048 KiB
> 
> Just a thought.

Yep this is exactly how I've just reworked it.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ