Messages in this thread | | | Date | Wed, 10 Apr 2024 17:51:28 +0200 | Subject | Re: [PATCH] mm/shmem: Inline shmem_is_huge() for disabled transparent hugepages | From | David Hildenbrand <> |
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On 10.04.24 17:26, Sumanth Korikkar wrote: > On Wed, Apr 10, 2024 at 02:34:35PM +0200, David Hildenbrand wrote: >> On 09.04.24 17:54, Sumanth Korikkar wrote: >>> In order to minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y), >>> compiler might choose to make a regular function call (out-of-line) for >>> shmem_is_huge() instead of inlining it. When transparent hugepages are >>> disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation >>> error. >>> >>> mm/shmem.c: In function ‘shmem_getattr’: >>> ./include/linux/huge_mm.h:383:27: note: in expansion of macro ‘BUILD_BUG’ >>> 383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; }) >>> | ^~~~~~~~~ >>> mm/shmem.c:1148:33: note: in expansion of macro ‘HPAGE_PMD_SIZE’ >>> 1148 | stat->blksize = HPAGE_PMD_SIZE; >>> >>> To prevent the possible error, always inline shmem_is_huge() when >>> transparent hugepages are disabled. >>> >> >> Do you know which commit introduced that? > Hi David, > > Currently with CONFIG_CC_OPTIMIZE_FOR_SIZE=y and expirementing with > -fPIC kernel compiler option, I could see this error on s390.
Got it. I assume on Linus' tree, not mm/unstable?
> > However, default kernel compiler options doesnt end up with the above > pattern right now.
Okay, just asking if this is related to recent HPAGE_PMD_SIZE changes:
commit c1a1e497a3d5711dbf8fa6d7432d6b83ec18c26f Author: Peter Xu <peterx@redhat.com> Date: Wed Mar 27 11:23:22 2024 -0400
mm: make HPAGE_PXD_* macros even if !THP
Which is still in mm-unstable and not upstream.
-- Cheers,
David / dhildenb
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