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]
Date:   Fri, 14 Apr 2023 11:34:03 +0200 (CEST)
From:   Miroslav Benes <mbenes@...e.cz>
To:     Luis Chamberlain <mcgrof@...nel.org>
cc:     david@...hat.com, patches@...ts.linux.dev,
        linux-modules@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, pmladek@...e.com,
        petr.pavlu@...e.com, prarit@...hat.com,
        torvalds@...ux-foundation.org, gregkh@...uxfoundation.org,
        rafael@...nel.org, christophe.leroy@...roup.eu, tglx@...utronix.de,
        peterz@...radead.org, song@...nel.org, rppt@...nel.org,
        dave@...olabs.net, willy@...radead.org, vbabka@...e.cz,
        mhocko@...e.com, dave.hansen@...ux.intel.com,
        colin.i.king@...il.com, jim.cromie@...il.com,
        catalin.marinas@....com, jbaron@...mai.com,
        rick.p.edgecombe@...el.com
Subject: Re: [PATCH v3 2/2] modules/kmod: replace implementation with a
 semaphore

On Thu, 13 Apr 2023, Luis Chamberlain wrote:

> Simplify the concurrency delimiter we use for kmod with the semaphore.
> I had used the kmod strategy to try to implement a similar concurrency
> delimiter for the kernel_read*() calls from the finit_module() path
> so to reduce vmalloc() memory pressure. That effort didn't provide yet
> conclusive results, but one thing that became clear is we can use
> the suggested alternative solution with semaphores which Linus hinted
> at instead of using the atomic / wait strategy.
> 
> I've stress tested this with kmod test 0008:
> 
> time /data/linux-next/tools/testing/selftests/kmod/kmod.sh -t 0008
> 
> And I get only a *slight* delay. That delay however is small, a few
> seconds for a full test loop run that runs 150 times, for about ~30-40
> seconds. The small delay is worth the simplfication IMHO.
> 
> Signed-off-by: Luis Chamberlain <mcgrof@...nel.org>

Reviewed-by: Miroslav Benes <mbenes@...e.cz>

M

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ