linux-kernel - Re: [PATCH v2 2/2] lib: make a test module with set/clear bit

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Message-ID: <20200220110347.00005557@intel.com>
Date:   Thu, 20 Feb 2020 11:03:47 -0800
From:   Jesse Brandeburg <jesse.brandeburg@...el.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>,
        <x86@...nel.org>, <linux-kernel@...r.kernel.org>,
        <linux@...musvillemoes.dk>, <andriy.shevchenko@...el.com>,
        <dan.j.williams@...el.com>
Subject: Re: [PATCH v2 2/2] lib: make a test module with set/clear bit

On Thu, 20 Feb 2020 19:10:33 +0100 Peter wrote:
> On Thu, Feb 20, 2020 at 09:37:22AM -0800, Jesse Brandeburg wrote:
> > Test some bit clears/sets to make sure assembly doesn't change.
> > Instruct Kbuild to build this file with extra warning level -Wextra,
> > to catch new issues, and also doesn't hurt to build with C=1.
> > 
> > This was used to test changes to arch/x86/include/asm/bitops.h.
> > 
> > Recommended usage:
> > make defconfig
> > scripts/config -m CONFIG_TEST_BITOPS
> > make modules_prepare
> > make C=1 W=1 lib/test_bitops.ko
> > objdump -S -d lib/test_bitops.ko  
> 
> I only applied this second patch:
> 
> # sparse --version
> 0.6.0 (Debian: 0.6.0-3+b1)

Thanks for the review! The module was created to verify assembly didn't
change before/after, but it's not a reproducer.  Let me fix that (I had
skipped that step as I originally didn't plan to upstream the
test-patch).