Re: [PATCH v7 12/15] sh: Drop cache flush of the zero page at boot
Geert Uytterhoeven <[email protected]> Mon, 1 Jun 2026 10:11:45 +0200
| Newsgroups | org.kernel.vger.linux-sh,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-hardening,org.kernel.vger.linux-kernel,org.kvack.linux-mm,org.ozlabs.lists.linuxppc-dev |
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| Message-ID | <CAMuHMdXp0qp38vHJTDFMrY-AUDXPSJtc5Dds_qu58FSeS_242w@mail.gmail.com> |
On Fri, 29 May 2026 at 17:02, Ard Biesheuvel <[email protected]> wrote: > From: Ard Biesheuvel <[email protected]> > > SuperH performs cache maintenance on the zero page during boot, > presumably because before commit > > 6215d9f4470f ("arch, mm: consolidate empty_zero_page") > > the zero page did double duty as a boot params region, and was cleared > separately, as it was not part of BSS. The memset() in question was > dropped by that commit, but the __flush_wback_region() call remained. > > As empty_zero_page[] has been moved to BSS, it can be treated as any > other BSS memory, and so the cache flush can be dropped. > > Cc: Yoshinori Sato <[email protected]> > Cc: Rich Felker <[email protected]> > Cc: John Paul Adrian Glaubitz <[email protected]> > Cc: Mike Rapoport <[email protected]> > Cc: Geert Uytterhoeven <[email protected]> > Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Geert Uytterhoeven <[email protected]> Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected] In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds