Changelog: v2 - v3 - Addressed David's comments about one change per patch: * Splited changes to platforms into 4 patches * Made "do not zero vmemmap_buf" as a separate patch v1 - v2 - Per request, added s390 to deferred "struct page" zeroing - Collected performance data on x86 which proofs the importance to keep memset() as prefetch (see below). When deferred struct page initialization feature is enabled, we get a performance gain of initializing vmemmap in parallel after other CPUs are started. However, we still zero the memory for vmemmap using one boot CPU. This patch-set fixes the memset-zeroing limitation by deferring it as well. Performance gain on SPARC with 32T: base: https://hastebin.com/ozanelatat.go fix: https://hastebin.com/utonawukof.go As you can see without the fix it takes: 97.89s to boot With the fix it takes: 46.91 to boot. Performance gain on x86 with 1T: base: https://hastebin.com/uvifasohon.pas fix: https://hastebin.com/anodiqaguj.pas On Intel we save 10.66s/T while on SPARC we save 1.59s/T. Intel has twice as many pages, and also fewer nodes than SPARC (sparc 32 nodes, vs. intel 8 nodes). It takes one thread 11.25s to zero vmemmap on Intel for 1T, so it should take additional 11.25 / 8 = 1.4s (this machine has 8 nodes) per node to initialize the memory, but it takes only additional 0.456s per node, which means on Intel we also benefit from having memset() and initializing all other fields in one place. Pavel Tatashin (9): sparc64: simplify vmemmap_populate mm: defining memblock_virt_alloc_try_nid_raw mm: add "zero" argument to vmemmap allocators mm: do not zero vmemmap_buf mm: zero struct pages during initialization sparc64: teach sparc not to zero struct pages memory x86: teach x86 not to zero struct pages memory powerpc: teach platforms not to zero struct pages memory s390: teach platforms not to zero struct pages memory arch/powerpc/mm/init_64.c | 4 +- arch/s390/mm/vmem.c | 5 ++- arch/sparc/mm/init_64.c | 26 +++++++---------------- arch/x86/mm/init_64.c | 3 +- include/linux/bootmem.h | 3 ++ include/linux/mm.h | 15 +++++++++++-- mm/memblock.c | 46 ++++++++++++++++++++++++++++++++++++------ mm/page_alloc.c | 3 ++ mm/sparse-vmemmap.c | 48 +++++++++++++++++++++++++++++--------------- 9 files changed, 103 insertions(+), 50 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
