From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 348547472 for ; Sun, 13 Nov 2022 22:59:25 +0000 (UTC) Received: from zn.tnic (p200300ea9733e773329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9733:e773:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 1AC381EC02DD; Sun, 13 Nov 2022 23:59:24 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1668380364; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=Oas9F0wtXybTRTTzPZachjZwGtcIAX+ns8IXE6OPciY=; b=j9IPFGYKPrOyhh97vec2lylSkfCbCmfRNuL+mZhywfUIVkPh/DZRIxTGzZYXY8p1SknfRt oihJkFMwTq/fBy/1DSV//OFCuCKgb0pxQQEf0Ds3lsdwOFWNkZK4yVV+RcAeMlcRZuqUYg EDpt1udJMTXwX0ZV7bBYmjzUN+kvIZg= Date: Sun, 13 Nov 2022 23:59:23 +0100 From: Borislav Petkov To: Thiago Macieira Cc: Ashok Raj , "gregkh@linuxfoundation.org" , "Luck, Tony" , "Joseph, Jithu" , "hdegoede@redhat.com" , "markgross@kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "dave.hansen@linux.intel.com" , "x86@kernel.org" , "hpa@zytor.com" , "linux-kernel@vger.kernel.org" , "platform-driver-x86@vger.kernel.org" , "patches@lists.linux.dev" , "Shankar, Ravi V" , "Jimenez Gonzalez, Athenas" , "Mehta, Sohil" Subject: Re: [PATCH v2 12/14] platform/x86/intel/ifs: Add current_batch sysfs entry Message-ID: References: <20221021203413.1220137-1-jithu.joseph@intel.com> <1745359.VLH7GnMWUR@tjmaciei-mobl5> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1745359.VLH7GnMWUR@tjmaciei-mobl5> On Sun, Nov 13, 2022 at 01:40:56PM -0800, Thiago Macieira wrote: > On Sunday, 13 November 2022 07:58:52 PST Borislav Petkov wrote: > > * simply try *all* files in a directory > > By the way, we don't want that. > > It's possible that different steppings of the same generation will have the > same test scan files, with the extended signature informing that they are valid > for this stepping too (see find_matching_signature())), because these files are > going to be pretty big, in the order of a hundred MB each. That means we will > either see symlinked or hardlinked files in the directory. > > If you blindly try them all, you're going to spend twice or three times as > long as necessary to complete the scan. With the timeout in question for at > least Sapphire Rapids, we're talking about a difference measured in hours. You either have files which are valid and which will get run on the CPU or those which will fail the header check. The header check happens in msecs. So I have no clue what "hours" you're talking about here. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette