Sunshine (she/her)@lemmy.ca to Linux@programming.devEnglish · 1 day agoLinux Kernel Patches To Use AMD INVLPGB Instruction Show Huge Speed-Upwww.phoronix.comexternal-linkmessage-square12fedilinkarrow-up1109arrow-down12cross-posted to: [email protected]
arrow-up1107arrow-down1external-linkLinux Kernel Patches To Use AMD INVLPGB Instruction Show Huge Speed-Upwww.phoronix.comSunshine (she/her)@lemmy.ca to Linux@programming.devEnglish · 1 day agomessage-square12fedilinkcross-posted to: [email protected]
minus-squareSteveTech@programming.devlinkfedilinkEnglisharrow-up6·20 hours agoI couldn’t find a hard answer to whether this supports EPYC only, or Ryzen too; so I put together this script to read the CPUID to detect for INVLPGB support according to the AMD64 Programmer’s Manual, and my 7800X3D does not support INVLPGB. (Let me know if I’ve made an error though!) Code #include <stdio.h> #include <stdint.h> int main() { uint32_t eax, ebx, ecx, edx; eax = 0x80000008; __asm__ __volatile__ ( "cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (eax) ); printf("EBX: 0x%x\n", ebx); if (ebx & (1 << 3)) { printf("CPU supports INVLPGB\n"); } else { printf("CPU does not support INVLPGB\n"); } return 0; }
I couldn’t find a hard answer to whether this supports EPYC only, or Ryzen too; so I put together this script to read the CPUID to detect for
INVLPGB
support according to the AMD64 Programmer’s Manual, and my 7800X3D does not supportINVLPGB
.(Let me know if I’ve made an error though!)
Code
#include <stdio.h> #include <stdint.h> int main() { uint32_t eax, ebx, ecx, edx; eax = 0x80000008; __asm__ __volatile__ ( "cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (eax) ); printf("EBX: 0x%x\n", ebx); if (ebx & (1 << 3)) { printf("CPU supports INVLPGB\n"); } else { printf("CPU does not support INVLPGB\n"); } return 0; }