Re: [v2 0/5] parallelized "struct page" zeroing
On Fri, Mar 24, 2017 at 03:19:47PM -0400, Pavel Tatashin wrote: > Changelog: > 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. My question was how long it takes if you memset in neither place.
Re: [v2 0/5] parallelized "struct page" zeroing
On Fri, Mar 24, 2017 at 03:19:47PM -0400, Pavel Tatashin wrote: > Changelog: > 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. My question was how long it takes if you memset in neither place.
[v2 0/5] parallelized "struct page" zeroing
Changelog: 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 (5): sparc64: simplify vmemmap_populate mm: defining memblock_virt_alloc_try_nid_raw mm: add "zero" argument to vmemmap allocators mm: zero struct pages during initialization mm: 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(-)
[v2 0/5] parallelized "struct page" zeroing
Changelog: 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 (5): sparc64: simplify vmemmap_populate mm: defining memblock_virt_alloc_try_nid_raw mm: add "zero" argument to vmemmap allocators mm: zero struct pages during initialization mm: 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(-)
