| Message ID | 20241217074640.1064510-1-sourabhjain@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d629d7a8efc33d05d62f4805c0ffb44727e3d99f |
| Headers | show |
| Series | [v2] powerpc/book3s64/hugetlb: Fix disabling hugetlb when fadump is active | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/github-powerpc_ppctests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_selftests | success | Successfully ran 8 jobs. |
| snowpatch_ozlabs/github-powerpc_sparse | success | Successfully ran 4 jobs. |
| snowpatch_ozlabs/github-powerpc_clang | success | Successfully ran 5 jobs. |
| snowpatch_ozlabs/github-powerpc_kernel_qemu | success | Successfully ran 21 jobs. |
On Tue, 17 Dec 2024 13:16:40 +0530, Sourabh Jain wrote: > Commit 8597538712eb ("powerpc/fadump: Do not use hugepages when fadump > is active") disabled hugetlb support when fadump is active by returning > early from hugetlbpage_init():arch/powerpc/mm/hugetlbpage.c and not > populating hpage_shift/HPAGE_SHIFT. > > Later, commit 2354ad252b66 ("powerpc/mm: Update default hugetlb size > early") moved the allocation of hpage_shift/HPAGE_SHIFT to early boot, > which inadvertently re-enabled hugetlb support when fadump is active. > > [...] Applied to powerpc/next. [1/1] powerpc/book3s64/hugetlb: Fix disabling hugetlb when fadump is active https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=d629d7a8efc33d05d62f4805c0ffb44727e3d99f Thanks
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h index 18a3028ac3b6..dad2e7980f24 100644 --- a/arch/powerpc/include/asm/hugetlb.h +++ b/arch/powerpc/include/asm/hugetlb.h @@ -15,6 +15,15 @@ extern bool hugetlb_disabled; +static inline bool hugepages_supported(void) +{ + if (hugetlb_disabled) + return false; + + return HPAGE_SHIFT != 0; +} +#define hugepages_supported hugepages_supported + void __init hugetlbpage_init_defaultsize(void); int slice_is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
Commit 8597538712eb ("powerpc/fadump: Do not use hugepages when fadump is active") disabled hugetlb support when fadump is active by returning early from hugetlbpage_init():arch/powerpc/mm/hugetlbpage.c and not populating hpage_shift/HPAGE_SHIFT. Later, commit 2354ad252b66 ("powerpc/mm: Update default hugetlb size early") moved the allocation of hpage_shift/HPAGE_SHIFT to early boot, which inadvertently re-enabled hugetlb support when fadump is active. Fix this by implementing hugepages_supported() on powerpc. This ensures that disabling hugetlb for the fadump kernel is independent of hpage_shift/HPAGE_SHIFT. Fixes: 2354ad252b66 ("powerpc/mm: Update default hugetlb size early") CC: Aneesh Kumar K.V <aneesh.kumar@kernel.org> CC: Hari Bathini <hbathini@linux.ibm.com> CC: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mahesh Salgaonkar <mahesh@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com> --- Changelog: Since v1: https://lore.kernel.org/all/20241202054310.928610-1-sourabhjain@linux.ibm.com/ - Change return type of hugepages_supported() to bool - Add a Reviewed-by Note: Even with this fix included, it is possible to enable gigantic pages in the fadump kernel. IIUC, gigantic pages were never disabled for the fadump kernel. Currently, gigantic pages are allocated during early boot as long as the respective hstate is supported by the architecture. I will introduce some changes in the generic hugetlb code to allow the architecture to decide on supporting gigantic pages on the go. Bringing gigantic page allocation under hugepages_supported() does work for powerpc but I need verify the impact on other architectures. Regarding the Fixes tag: This patch fixes a bug inadvertently introduced by the commit mentioned under Fixes tag in the commit message. Feel free to remove the tag if it is unnecessary. --- arch/powerpc/include/asm/hugetlb.h | 9 +++++++++ 1 file changed, 9 insertions(+)