61f77eda9b
Currently we have many duplicates in definitions around follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this patch tries to remove the m. The basic idea is to put the default implementation for these functions in mm/hugetlb.c as weak symbols (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement arch-specific code only when the arch needs it. For follow_huge_addr(), only powerpc and ia64 have their own implementation, and in all other architectures this function just returns ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as default. As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to always return 0 in your architecture (like in ia64 or sparc,) it's never called (the callsite is optimized away) no matter how implemented it is. So in such architectures, we don't need arch-specific implementation. In some architecture (like mips, s390 and tile,) their current arch-specific follow_huge_(pmd|pud)() are effectively identical with the common code, so this patch lets these architecture use the common code. One exception is metag, where pmd_huge() could return non-zero but it expects follow_huge_pmd() to always return NULL. This means that we need arch-specific implementation which returns NULL. This behavior looks strange to me (because non-zero pmd_huge() implies that the architecture supports PMD-based hugepage, so follow_huge_pmd() can/should return some relevant value,) but that's beyond this cleanup patch, so let's keep it. Justification of non-trivial changes: - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE is true when follow_huge_pmd() can be called (note that pmd_huge() has the same check and always returns 0 for !MACHINE_HAS_HPAGE.) - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common code. This patch forces these archs use PMD_MASK, but it's OK because they are identical in both archs. In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20. In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but PTE_ORDER is always 0, so these are identical. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Steve Capper <steve.capper@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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.. | ||
boot | ||
common | ||
configs | ||
crypto | ||
firmware | ||
include | ||
kernel | ||
kvm | ||
lib | ||
mach-asm9260 | ||
mach-at91 | ||
mach-axxia | ||
mach-bcm | ||
mach-berlin | ||
mach-clps711x | ||
mach-cns3xxx | ||
mach-davinci | ||
mach-dove | ||
mach-ebsa110 | ||
mach-efm32 | ||
mach-ep93xx | ||
mach-exynos | ||
mach-footbridge | ||
mach-gemini | ||
mach-highbank | ||
mach-hisi | ||
mach-imx | ||
mach-integrator | ||
mach-iop13xx | ||
mach-iop32x | ||
mach-iop33x | ||
mach-ixp4xx | ||
mach-keystone | ||
mach-ks8695 | ||
mach-lpc32xx | ||
mach-mediatek | ||
mach-meson | ||
mach-mmp | ||
mach-moxart | ||
mach-msm | ||
mach-mv78xx0 | ||
mach-mvebu | ||
mach-mxs | ||
mach-netx | ||
mach-nomadik | ||
mach-nspire | ||
mach-omap1 | ||
mach-omap2 | ||
mach-orion5x | ||
mach-picoxcell | ||
mach-prima2 | ||
mach-pxa | ||
mach-qcom | ||
mach-realview | ||
mach-rockchip | ||
mach-rpc | ||
mach-s3c24xx | ||
mach-s3c64xx | ||
mach-s5pv210 | ||
mach-sa1100 | ||
mach-shmobile | ||
mach-socfpga | ||
mach-spear | ||
mach-sti | ||
mach-sunxi | ||
mach-tegra | ||
mach-u300 | ||
mach-ux500 | ||
mach-versatile | ||
mach-vexpress | ||
mach-vt8500 | ||
mach-w90x900 | ||
mach-zynq | ||
mm | ||
net | ||
nwfpe | ||
oprofile | ||
plat-iop | ||
plat-omap | ||
plat-orion | ||
plat-pxa | ||
plat-samsung | ||
plat-versatile | ||
tools | ||
vfp | ||
xen | ||
Kconfig | ||
Kconfig-nommu | ||
Kconfig.debug | ||
Makefile |