| Message ID | 20201029162718.29910-1-david@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | powernv/memtrace: don't abuse memory hot(un)plug infrastructure for memory allocations | expand |
On Thu, 29 Oct 2020 17:27:14 +0100, David Hildenbrand wrote: > powernv/memtrace is the only in-kernel user that rips out random memory > it never added (doesn't own) in order to allocate memory without a > linear mapping. Let's stop abusing memory hot(un)plug infrastructure for > that - use alloc_contig_pages() for allocating memory and remove the > linear mapping manually. > > The original idea was discussed in: > https://lkml.kernel.org/r/48340e96-7e6b-736f-9e23-d3111b915b6e@redhat.com > > [...] Applied to powerpc/next. [1/4] powerpc/mm: factor out creating/removing linear mapping https://git.kernel.org/powerpc/c/4abb1e5b63ac3281275315fc6b0cde0b9c2e2e42 [2/4] powerpc/mm: print warning in arch_remove_linear_mapping() https://git.kernel.org/powerpc/c/1f73ad3e8d755dbec52fcec98618a7ce4de12af2 [3/4] powerpc/mm: remove linear mapping if __add_pages() fails in arch_add_memory() https://git.kernel.org/powerpc/c/ca2c36cae9d48b180ea51259e35ab3d95d327df2 [4/4] powernv/memtrace: don't abuse memory hot(un)plug infrastructure for memory allocations https://git.kernel.org/powerpc/c/0bd4b96d99108b7ea9bac0573957483be7781d70 cheers
powernv/memtrace is the only in-kernel user that rips out random memory it never added (doesn't own) in order to allocate memory without a linear mapping. Let's stop abusing memory hot(un)plug infrastructure for that - use alloc_contig_pages() for allocating memory and remove the linear mapping manually. The original idea was discussed in: https://lkml.kernel.org/r/48340e96-7e6b-736f-9e23-d3111b915b6e@redhat.com I only tested allocations briefly via QEMU TCG - see patch #4 for more details. David Hildenbrand (4): powerpc/mm: factor out creating/removing linear mapping powerpc/mm: print warning in arch_remove_linear_mapping() powerpc/mm: remove linear mapping if __add_pages() fails in arch_add_memory() powernv/memtrace: don't abuse memory hot(un)plug infrastructure for memory allocations arch/powerpc/mm/mem.c | 48 +++++--- arch/powerpc/platforms/powernv/Kconfig | 8 +- arch/powerpc/platforms/powernv/memtrace.c | 134 ++++++++-------------- include/linux/memory_hotplug.h | 3 + 4 files changed, 86 insertions(+), 107 deletions(-)