On 02/14/2019 10:52 AM, Vlastimil Babka wrote:
On 2/13/19 8:30 PM, Dave Hansen wrote:-#if (defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || defined(CONFIG_CMA) +#ifdef CONFIG_COMPACTION_CORE static __init int gigantic_pages_init(void) { /* With compaction or CMA we can allocate gigantic pages at runtime */ diff --git a/fs/Kconfig b/fs/Kconfig index ac474a61be37..8fecd3ea5563 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -207,8 +207,9 @@ config HUGETLB_PAGE config MEMFD_CREATE def_bool TMPFS || HUGETLBFS-config ARCH_HAS_GIGANTIC_PAGE+config COMPACTION_CORE bool + default y if (MEMORY_ISOLATION && MIGRATION) || CMAThis takes a hard dependency (#if) and turns it into a Kconfig *default* that can be overridden. That seems like trouble.Shouldn't it be: config COMPACTION_CORE def_bool y depends on (MEMORY_ISOLATION && MIGRATION) || CMAAgreed. Also I noticed that it now depends on MIGRATION instead of COMPACTION. That intention is correct IMHO, but will fail to compile/link when both COMPACTION and CMA are disabled, and would need more changes in mm/internal.h and mm/compaction.c (possibly just replacing CMA in all "if defined CONFIG_COMPACTION || defined CONFIG_CMA" instances with COMPACTION_CORE, but there might be more problems, wanna try? :)
Let's be honest, that's a "typo" :) Migration is logical to me but that's because I don't know much about compaction. Thanks for noticing it. I'll take a look at what you propose to do too.
Also, I realized that COMPACTION_CORE is a wrong name, sorry about that. What the config really provides is alloc_contig_range(), so it should be named either CONFIG_CMA_CORE (as it provides contiguous memory allocation, but not the related reservation and accounting), or something like CONFIG_CONTIG_ALLOC. I would also move it from fs/Kconfig to mm/Kconfig.
No problem, I was not inspired either. I'll send a v3 with the renaming you propose.
Thanks!
Thank you. Alex
