Accelerating oracle workloads with vsphere 6.7 guest 1gb huge pages – an investigation journey into all things oracle and virtualization gas weed strain

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Also reading address mappings from the page table is time-consuming and resource-expensive, so CPUs are built with a cache for recently-used addresses: the Translation Lookaside Buffer (TLB). zyklon b gas effects However, the default TLB can only cache a certain number of address mappings. npower gas price per unit If a requested address mapping is not in the TLB (that is, the TLB is missed), the system still needs to read the page table to determine the physical to virtual address mapping.

Because of the relationship between application memory requirements and the size of pages used to cache address mappings, applications with large memory requirements are more likely to suffer performance degradation from TLB misses than applications with minimal memory requirements. It is therefore important to avoid TLB misses wherever possible.

The second method is the Linux 2.6 onwards implementation of what is called Huge Pages. power company near me Enabling HugePages makes it possible to support memory pages greater than the default (usually 4 KB). u save gas station grants pass The Huge page support is built on top of multiple page size support that is provided by most modern architectures. gas after eating red meat For example, x86 CPUs normally support 4K and 2M (1G if architecturally supported) page sizes, ia64 architecture supports multiple page sizes 4K, 8K, 64K, 256K, 1M, 4M, 16M,256M and ppc64 supports 4K and 16M.

Refer to Oracle Metalink Note “Disable Transparent HugePages on SLES11, RHEL6, RHEL7, OL6, OL7, and UEK2 and above (Doc ID 1557478.1)”. – Because Transparent HugePages are known to cause unexpected node reboots and performance problems with RAC, Oracle strongly advises to disable the use of Transparent HugePages. gas x chewables reviews In addition, Transparent Hugepages may cause problems even in a single-instance database environment with unexpected performance problems or delays. grade 6 electricity project As such, Oracle recommends disabling Transparent HugePages on all Database servers running Oracle.

• 1GB page vRAM backing is opportunistic and 1GB pages are allocated on a best effort basis. This includes cases where host CPUs do not have 1GB capabilities. gas in back shoulder To maximize the chances of having guest vRAM backed with 1GB pages, we recommended to start VMs requiring 1GB pages on a freshly booted host because over time the host RAM is fragmented.

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc eagerfpu pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch fsgsbase tsc_adjust bmi1 hle avx2 smep bmi2 invpcid rtm mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveopt xsavec ibpb ibrs stibp arat pku ospke spec_ctrl intel_stibp arch_capabilities

As per the Metalink note, ‘ As per unpublished Bug 17271305, the issue is in Oracle code. Ideally the fixed SGA would be in 2MB HugePages (it is small enough to fit into a 2MB huge page), but would require additional changes to Oracle code since the Linux shm*() interface only supports one hugepage size (whatever is set to default, either 2MB or 1GB).’.

Starting VMware vSphere 6.7, 1GB Huge page support is provided for VM’s vRAM with the caveats that the VM needs full memory reservations along with the fact that 1GB page vRAM backing is opportunistic and 1GB pages are allocated on a best effort basis. The opportunistic nature of 1GB pages extends to vSphere services such as HA and DRS that might not preserve 1GB page vRAM backing.