linux-kernel - Re: [PATCH] x86: Use clflush() instead of wbinvd() whenever possible when changing mapping

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, 24 Jul 2009 12:05:01 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Thomas Hellstrom <thellstrom@...are.com>
Cc:	linux-kernel@...r.kernel.org, mingo@...e.hu,
	venkatesh.pallipadi@...el.com
Subject: Re: [PATCH] x86: Use clflush() instead of wbinvd() whenever possible when changing mapping

Thomas Hellstrom <thellstrom@...are.com> writes:

> The current code uses wbinvd() when the area to flush is > 4MB. Although this
> may be faster than using clflush() the effect of wbinvd() on irq latencies
> may be catastrophical on systems with large caches. Therefore use clflush()

may be? You seem to miss some hard data here.

I wouldn't expect wbinvd to take longer than a ms or two, which 
is probably not catastrophic yet.

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/