Re: [PATCH blktests] Fix _get_page_size()

[Omar Sandoval <osandov@osandov.com>]

On Mon, Jun 22, 2026 at 08:38:48PM +0900, Shin'ichiro Kawasaki wrote:
> On Jun 20, 2026 / 09:11, Bart Van Assche wrote:
> > On 6/20/26 6:51 AM, Shin'ichiro Kawasaki wrote:
> > > On Jun 20, 2026 / 05:55, Bart Van Assche wrote:
> > > > On 6/20/26 3:26 AM, Shin'ichiro Kawasaki wrote:
> > > > > This is a rather fundamental change, so I would like to ask opinions from
> > > > > other blktests users, especially Omar and Chaitanya. What do you think about
> > > > > the idea to add getconf to the requirement list?
> > > > 
> > > > CONFIG_PAGE_SHIFT was introduced in the Linux kernel in February 2024
> > > > (commit ba89f9c8ccba ("arch: consolidate existing CONFIG_PAGE_SIZE_*KB
> > > > definitions")). Older kernels had CONFIG_PAGE_SIZE_4KB,
> > > > CONFIG_PAGE_SIZE_16KB, etc. This means that it is possible to derive the
> > > > kernel page size from the kernel configuration file for all upstream and
> > > > distro kernels, isn't it?
> > > 
> > > I checked the commit is in the tag v6.9. My Debian bookworm system has kernel
> > > v6.1, then the config file at /boot does not have CONFIG_PAGE_SHIFT as expected.
> > > But it does not have CONFIG_PAGE_SIZE_* either... I'm still afraid that kernel
> > > config file approach is not reliable.
> > 
> > Right, for older kernels CONFIG_PAGE_SIZE_*KB is only available for some
> > but not for all supported architectures.
> > 
> > It is not clear to me where the desire to avoid the dependency on
> > getconf comes from? As far as I know it is available on all Linux
> > distro's. Since it is typically included in the C library package it
> > should not introduce a new dependency.
> 
> I think less dependent is the better in general, and wanted to confirm that
> it is fine for everybody. If there is no voice to object, I will create a
> patch to add getconf to the requirement list.

I agree with Bart, getconf is ubiquitous enough that it's not worth
trying to hack around its absence. In my opinion, parsing kernel config
options should be a last resort. If anyone complains about the getconf
dependency in the future, I think it'd be better to add a simple
src/pagesize.c file that uses sysconf(_SC_PAGESIZE), but I don't expect
that to be necessary.

Omar