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: <177f56cd-6e10-4d2e-7a3e-23276222ba19@yandex-team.ru>
Date:   Wed, 22 May 2019 19:09:22 +0300
From:   Konstantin Khlebnikov <khlebnikov@...dex-team.ru>
To:     Michal Hocko <mhocko@...nel.org>
Cc:     linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>,
        linux-kernel@...r.kernel.org, Roman Gushchin <guro@...com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Johannes Weiner <hannes@...xchg.org>
Subject: Re: [PATCH] proc/meminfo: add MemKernel counter

On 22.05.2019 18:52, Michal Hocko wrote:
> On Wed 22-05-19 17:40:09, Konstantin Khlebnikov wrote:
>> Some kinds of kernel allocations are not accounted or not show in meminfo.
>> For example vmalloc allocations are tracked but overall size is not shown
>> for performance reasons. There is no information about network buffers.
>>
>> In most cases detailed statistics is not required. At first place we need
>> information about overall kernel memory usage regardless of its structure.
>>
>> This patch estimates kernel memory usage by subtracting known sizes of
>> free, anonymous, hugetlb and caches from total memory size: MemKernel =
>> MemTotal - MemFree - Buffers - Cached - SwapCached - AnonPages - Hugetlb.
> 
> Why do we need to export something that can be calculated in the
> userspace trivially? Also is this really something the number really
> meaningful? Say you have a driver that exports memory to the userspace
> via mmap but that memory is not accounted. Is this really a kernel
> memory?
> 

It may be trivial right now but not fixed.
Adding new kinds of memory may change this definition.
For example hypothetical 'GPU buffers' may be handled as 'userspace' memory.

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ