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Since the life time of the pagerefs is > also the lifetime of the fb_deferred_io object, storing the pointer here > makes snese. > > This eliminates the need for all of the logic around setting and > maintaining page->index,mapping which we remove. > > This eliminates the use of folio_mkclean() entirely but otherwise should > have no functional change. > > Signed-off-by: Lorenzo Stoakes Andrew - Sorry to be a pain but could you please apply the attached fix-patch to avoid build bot failures when randconfig generates invalid configurations. The defio mechanism entirely relies upon the page faulting mechanism, and thus an MMU to function. This was previously masked, because folio_mkclean() happens to have a !CONFIG_MMU stub. It really doesn't make sense to apply such a stub for mapping_wrprotect_page() for architectures without an MMU. Instead, correctly express the actual dependency in Kconfig, which should prevent randconfig from doing the wrong thing and also helps document this fact about defio. Thanks! ----8<---- >From 32abcfbb8dea92d9a8a99e6a86f45a1823a75c59 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Sat, 1 Feb 2025 16:56:02 +0000 Subject: [PATCH] fbdev: have CONFIG_FB_DEFERRED_IO depend on CONFIG_MMU Frame buffer deferred I/O is entirely reliant on the page faulting mechanism (and thus, an MMU) to function. Express this dependency in the Kconfig, as otherwise randconfig could generate invalid configurations resulting in build errors. Signed-off-by: Lorenzo Stoakes Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202502020030.MnEJ847Z-lkp@intel.com/ --- drivers/video/fbdev/core/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/video/fbdev/core/Kconfig b/drivers/video/fbdev/core/Kconfig index d554d8c543d4..154804914680 100644 --- a/drivers/video/fbdev/core/Kconfig +++ b/drivers/video/fbdev/core/Kconfig @@ -135,6 +135,7 @@ config FB_SYSMEM_FOPS config FB_DEFERRED_IO bool depends on FB_CORE + depends on MMU config FB_DMAMEM_HELPERS bool -- 2.48.1