From: Steven Rostedt <rostedt@goodmis.org>
To: kernel-janitors@vger.kernel.org
Subject: Re: Difficulties for compilation without extra optimisation
Date: Sun, 03 Dec 2017 21:22:56 +0000 [thread overview]
Message-ID: <20171203162256.4ea0750d@vmware.local.home> (raw)
In-Reply-To: <1512314250.3673.6.camel@primarydata.com>
On Sun, 3 Dec 2017 15:17:32 +0000
Trond Myklebust <trondmy@primarydata.com> wrote:
> > I would like to check corresponding build results then without extra
> > optimisation applied by the compiler.
> > But I got surprised by error messages for a command like the
> > following.
> >
> > elfring@Sonne:~/Projekte/Linux/next-patched> my_cc=/usr/bin/gcc-7 &&
> > LANG=C make -j4 CC="${my_cc}" HOSTCC="${my_cc}" EXTRA_CFLAGS='-O0'
> > allmodconfig fs/nfs/write.o
Why would you compile the kernel without optimization? There's many
places in the kernel that WILL NOT BUILD without optimization. In fact,
we do a lot of tricks to make sure that things work the way we expect
it to, because we add broken code that only gets compiled out when gcc
optimizes the code the way we expect it to be, and the kernel build
will break otherwise.
-- Steve
WARNING: multiple messages have this Message-ID (diff)
From: rostedt at goodmis.org (Steven Rostedt)
Subject: [Linux-kselftest-mirror] Difficulties for compilation without extra optimisation
Date: Sun, 3 Dec 2017 16:22:56 -0500 [thread overview]
Message-ID: <20171203162256.4ea0750d@vmware.local.home> (raw)
In-Reply-To: <1512314250.3673.6.camel@primarydata.com>
On Sun, 3 Dec 2017 15:17:32 +0000
Trond Myklebust <trondmy at primarydata.com> wrote:
> > I would like to check corresponding build results then without extra
> > optimisation applied by the compiler.
> > But I got surprised by error messages for a command like the
> > following.
> >
> > elfring at Sonne:~/Projekte/Linux/next-patched> my_cc=/usr/bin/gcc-7 &&
> > LANG=C make -j4 CC="${my_cc}" HOSTCC="${my_cc}" EXTRA_CFLAGS='-O0'
> > allmodconfig fs/nfs/write.o
Why would you compile the kernel without optimization? There's many
places in the kernel that WILL NOT BUILD without optimization. In fact,
we do a lot of tricks to make sure that things work the way we expect
it to, because we add broken code that only gets compiled out when gcc
optimizes the code the way we expect it to be, and the kernel build
will break otherwise.
-- Steve
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WARNING: multiple messages have this Message-ID (diff)
From: rostedt@goodmis.org (Steven Rostedt)
Subject: [Linux-kselftest-mirror] Difficulties for compilation without extra optimisation
Date: Sun, 3 Dec 2017 16:22:56 -0500 [thread overview]
Message-ID: <20171203162256.4ea0750d@vmware.local.home> (raw)
Message-ID: <20171203212256.0_zF63ZWD_UQmaanKF5tCal77PZ2fc_iL7fTRM5WUf8@z> (raw)
In-Reply-To: <1512314250.3673.6.camel@primarydata.com>
On Sun, 3 Dec 2017 15:17:32 +0000
Trond Myklebust <trondmy@primarydata.com> wrote:
> > I would like to check corresponding build results then without extra
> > optimisation applied by the compiler.
> > But I got surprised by error messages for a command like the
> > following.
> >
> > elfring at Sonne:~/Projekte/Linux/next-patched> my_cc=/usr/bin/gcc-7 &&
> > LANG=C make -j4 CC="${my_cc}" HOSTCC="${my_cc}" EXTRA_CFLAGS='-O0'
> > allmodconfig fs/nfs/write.o
Why would you compile the kernel without optimization? There's many
places in the kernel that WILL NOT BUILD without optimization. In fact,
we do a lot of tricks to make sure that things work the way we expect
it to, because we add broken code that only gets compiled out when gcc
optimizes the code the way we expect it to be, and the kernel build
will break otherwise.
-- Steve
--
To unsubscribe from this list: send the line "unsubscribe linux-kselftest" in
the body of a message to majordomo at vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
WARNING: multiple messages have this Message-ID (diff)
From: Steven Rostedt <rostedt@goodmis.org>
To: Trond Myklebust <trondmy@primarydata.com>
Cc: "linux-kselftest@vger.kernel.org"
<linux-kselftest@vger.kernel.org>,
"elfring@users.sourceforge.net" <elfring@users.sourceforge.net>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
"kernel-janitors@vger.kernel.org"
<kernel-janitors@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"peterz@infradead.org" <peterz@infradead.org>
Subject: Re: Difficulties for compilation without extra optimisation
Date: Sun, 3 Dec 2017 16:22:56 -0500 [thread overview]
Message-ID: <20171203162256.4ea0750d@vmware.local.home> (raw)
In-Reply-To: <1512314250.3673.6.camel@primarydata.com>
On Sun, 3 Dec 2017 15:17:32 +0000
Trond Myklebust <trondmy@primarydata.com> wrote:
> > I would like to check corresponding build results then without extra
> > optimisation applied by the compiler.
> > But I got surprised by error messages for a command like the
> > following.
> >
> > elfring@Sonne:~/Projekte/Linux/next-patched> my_cc=/usr/bin/gcc-7 &&
> > LANG=C make -j4 CC="${my_cc}" HOSTCC="${my_cc}" EXTRA_CFLAGS='-O0'
> > allmodconfig fs/nfs/write.o
Why would you compile the kernel without optimization? There's many
places in the kernel that WILL NOT BUILD without optimization. In fact,
we do a lot of tricks to make sure that things work the way we expect
it to, because we add broken code that only gets compiled out when gcc
optimizes the code the way we expect it to be, and the kernel build
will break otherwise.
-- Steve
next prev parent reply other threads:[~2017-12-03 21:22 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-07 16:53 [PATCH RFC v1] nfs/write: Use common error handling code in nfs_lock_and_join_requests() SF Markus Elfring
2017-11-07 16:53 ` SF Markus Elfring
2017-12-03 14:15 ` Difficulties for compilation without extra optimisation SF Markus Elfring
2017-12-03 14:15 ` SF Markus Elfring
2017-12-03 14:15 ` [Linux-kselftest-mirror] " SF Markus Elfring
2017-12-03 14:15 ` elfring
2017-12-03 15:17 ` Trond Myklebust
2017-12-03 15:17 ` Trond Myklebust
2017-12-03 15:17 ` Trond Myklebust
2017-12-03 15:17 ` [Linux-kselftest-mirror] " Trond Myklebust
2017-12-03 15:17 ` trondmy
2017-12-03 21:22 ` Steven Rostedt [this message]
2017-12-03 21:22 ` Steven Rostedt
2017-12-03 21:22 ` [Linux-kselftest-mirror] " Steven Rostedt
2017-12-03 21:22 ` rostedt
2017-12-03 21:56 ` SF Markus Elfring
2017-12-03 21:56 ` SF Markus Elfring
2017-12-03 21:56 ` [Linux-kselftest-mirror] " SF Markus Elfring
2017-12-03 21:56 ` elfring
2017-12-04 2:40 ` Steven Rostedt
2017-12-04 2:40 ` Steven Rostedt
2017-12-04 2:40 ` [Linux-kselftest-mirror] " Steven Rostedt
2017-12-04 2:40 ` rostedt
2017-12-04 9:55 ` SF Markus Elfring
2017-12-04 9:55 ` SF Markus Elfring
2017-12-04 9:55 ` [Linux-kselftest-mirror] " SF Markus Elfring
2017-12-04 9:55 ` elfring
2017-12-04 9:00 ` SF Markus Elfring
2017-12-04 9:00 ` SF Markus Elfring
2017-12-04 9:00 ` [Linux-kselftest-mirror] " SF Markus Elfring
2017-12-04 9:00 ` elfring
2017-12-04 9:48 ` Steven Rostedt
2017-12-04 9:48 ` Steven Rostedt
2017-12-04 9:48 ` [Linux-kselftest-mirror] " Steven Rostedt
2017-12-04 9:48 ` rostedt
2017-12-04 10:18 ` SF Markus Elfring
2017-12-04 10:18 ` SF Markus Elfring
2017-12-04 10:18 ` [Linux-kselftest-mirror] " SF Markus Elfring
2017-12-04 10:18 ` elfring
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