From: Josh Poimboeuf <jpoimboe@redhat.com>
To: speck@linutronix.de
Subject: [MODERATED] Re: ***UNCHECKED*** Re: [PATCH v4 03/10] TAAv4 3
Date: Wed, 25 Sep 2019 17:05:15 -0500 [thread overview]
Message-ID: <20190925220515.s6ai3sdbyc7jwdi5@treble> (raw)
In-Reply-To: <20190904112758.GP3838@dhcp22.suse.cz>
On Wed, Sep 04, 2019 at 01:27:58PM +0200, speck for Michal Hocko wrote:
> On Wed 04-09-19 10:43:06, speck for Greg KH wrote:
> > On Wed, Sep 04, 2019 at 12:58:47AM -0700, speck for Pawan Gupta wrote:
> > > On Wed, Sep 04, 2019 at 08:11:55AM +0200, speck for Greg KH wrote:
> > > > On Wed, Sep 04, 2019 at 08:01:47AM +0200, speck for Jiri Kosina wrote:
> > > > > On Wed, 4 Sep 2019, speck for Greg KH wrote:
> > > > >
> > > > > > Did we ever have a reason to enable TSX? I thought no one used it as it
> > > > > > just didn't make any sense (as per Linus's old email about this)
> > > > > >
> > > > > > Who will be turning this on?
> > > > >
> > > > > We know about certain database vendor(s) who are somehow making use of TSX
> > > > > for whatever reason, so having such a knob would be nice of us.
> > > >
> > > > So they now need to explicitly enable it? Would that not break their
> > > > existing systems by forcing them to do an additional startup step, or is
> > > > that somehow ok here?
> > >
> > > For cases when the additional startup step is a problem, there is also
> > > a sysfs interface to control TSX after boot.
> >
> > And that extra step could be a problem. You had a machine that had TSX
> > enabled and the program used it. Upgrade your kernel and now you have
> > to add an additional step in order to use this (command line or sysfs).
> >
> > I am asking if this is going to be an issue for those systems that are
> > expecting a working TSX.
>
> Indeed. I was expecting auto|on|off semantic like other knobs with auto
> preserving the current semantic (disable on broken models) and off to
> override.
In the previous version of this patch set, Thomas requested the default
be 'tsx=off', which is what Pawan has done now in this version.
But I agree with Greg, that would break existing workloads. So I think
the default needs to be 'tsx=on', along with 'taa=full'.
--
Josh
next prev parent reply other threads:[~2019-09-25 22:05 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1567543894.git.pawan.kumar.gupta@linux.intel.com>
2019-09-23 12:47 ` [MODERATED] Re: [PATCH v4 01/10] TAAv4 1 Borislav Petkov
[not found] ` <20190904060028.GD7212@kroah.com>
[not found] ` <20190906072835.GD13480@guptapadev.amr>
[not found] ` <20190906092727.GA16843@kroah.com>
[not found] ` <20190910184223.GA7543@guptapadev.amr>
[not found] ` <20190910223334.GA21301@kroah.com>
[not found] ` <20190910233449.GA10041@agluck-desk2.amr.corp.intel.com>
2019-09-23 19:10 ` [MODERATED] Re: [PATCH v4 04/10] TAAv4 4 Greg KH
[not found] ` <20190911023223.GA8305@guptapadev.amr>
2019-09-23 19:13 ` Greg KH
2019-09-23 22:25 ` Pawan Gupta
2019-09-24 5:04 ` Greg KH
2019-09-24 10:48 ` Jiri Kosina
2019-09-24 13:31 ` Greg KH
2019-09-24 13:38 ` Jiri Kosina
2019-09-24 13:47 ` Greg KH
2019-09-24 23:25 ` Pawan Gupta
2019-09-27 7:01 ` Greg KH
2019-09-25 21:10 ` [MODERATED] Re: [PATCH v4 06/10] TAAv4 6 Kanth Ghatraju
2019-09-25 21:11 ` [MODERATED] [AUTOREPLY] [AUTOREPLY] Automatic reply: " Hatle, Mark
2019-09-26 1:15 ` [MODERATED] " Pawan Gupta
[not found] ` <20190904055711.GC7212@kroah.com>
[not found] ` <nycvar.YFH.7.76.1909040759580.31470@cbobk.fhfr.pm>
[not found] ` <20190904061155.GI7212@kroah.com>
[not found] ` <20190904075846.GD1321@guptapadev.amr>
[not found] ` <20190904084306.GA4925@kroah.com>
[not found] ` <20190904112758.GP3838@dhcp22.suse.cz>
2019-09-25 22:05 ` Josh Poimboeuf [this message]
2019-10-01 0:20 ` [MODERATED] Re: [PATCH v4 03/10] TAAv4 3 Pawan Gupta
2019-10-02 14:55 ` Borislav Petkov
2019-10-05 5:16 ` Pawan Gupta
2019-10-08 2:59 ` Josh Poimboeuf
2019-10-08 6:15 ` Pawan Gupta
2019-10-08 18:06 ` Dave Hansen
2019-10-08 18:36 ` [MODERATED] Re: ***UNCHECKED*** " Jiri Kosina
[not found] ` <20190904055406.GA7212@kroah.com>
[not found] ` <20190904074326.GB1321@guptapadev.amr>
[not found] ` <bfe6f7e0-22db-ce4d-ac3a-875482b43489@intel.com>
2019-09-25 22:13 ` [MODERATED] Re: [PATCH v4 02/10] TAAv4 2 Josh Poimboeuf
2019-09-26 0:46 ` Pawan Gupta
2019-09-25 22:30 ` Josh Poimboeuf
2019-09-30 23:26 ` Pawan Gupta
2019-09-30 23:32 ` [MODERATED] [AUTOREPLY] [MODERATED] [AUTOREPLY] Automatic reply: " James, Hengameh M
[not found] ` <5b6df5ee-a5b7-c281-de29-af6544b8abb6@intel.com>
[not found] ` <20190906074645.GE13480@guptapadev.amr>
2019-09-25 22:48 ` [MODERATED] Re: [PATCH v4 03/10] TAAv4 3 Josh Poimboeuf
2019-09-25 23:12 ` Dave Hansen
2019-09-25 23:22 ` Andrew Cooper
2019-09-26 1:13 ` Pawan Gupta
2019-09-26 2:34 ` Josh Poimboeuf
2019-09-26 7:15 ` Pawan Gupta
2019-09-26 13:54 ` Josh Poimboeuf
2019-09-26 17:57 ` Pawan Gupta
[not found] ` <d6fd9ad7-79f7-aab9-db31-a9a2ca03aa10@intel.com>
[not found] ` <20190906080828.GF13480@guptapadev.amr>
[not found] ` <00170736-0d97-4a48-2141-ffba4bb67199@intel.com>
2019-09-25 22:58 ` [MODERATED] Re: [PATCH v4 04/10] TAAv4 4 Josh Poimboeuf
2019-09-26 0:48 ` Pawan Gupta
2019-09-25 23:06 ` [MODERATED] Re: [PATCH v4 06/10] TAAv4 6 Josh Poimboeuf
2019-09-30 23:00 ` Pawan Gupta
2019-10-01 18:26 ` [MODERATED] Re: [PATCH v4 05/10] TAAv4 5 Pawan Gupta
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