Lines Matching refs:rdtsc
25 Does the OS/app use the rdtsc instruction at all?
30 At what frequency is the rdtsc instruction executed by either the OS
31 or any running apps? If the sum exceeds about 10,000 rdtsc instructions
38 If the OS/app does use rdtsc, will it behave incorrectly if "time goes
47 that uses rdtsc must be assumed to be TSC-sensitive and, as we
51 the family of rdtsc instructions are executed "natively" vs emulated.
52 Roughly speaking, native means rdtsc is fast but TSC-sensitive apps
56 all rdtsc instructions were native: "fast but potentially incorrect."
57 Starting at Xen 4.0, the default is that all rdtsc instructions are
60 how rdtsc instructions are executed differently for different domains.
68 All rdtsc instructions are emulated; this is the best choice when
109 To determine the frequency of rdtsc instructions that are emulated,
183 The rdtsc (read timestamp counter) instruction is used to read the
184 TSC register. The rdtscp instruction is a variant of rdtsc on recent
185 processors. We refer to these together as the rdtsc family of instructions,
186 or just "rdtsc". Instructions in the rdtsc family are non-privileged, but
187 privileged software may set a cpuid bit to cause all rdtsc family
189 then transparently "emulate" the results of the rdtsc instruction and
190 return control to the code following the rdtsc instruction.
193 fixed rate, Xen provides rdtsc emulation whenever necessary or when
195 relatively slow -- roughly 15-20 times slower than the rdtsc instruction
197 the rdtsc instruction at a high frequency (e.g. more than about 10,000 times
207 TSC-safe, rdtsc will execute at hardware speed; if it is not, rdtsc
269 by guest rdtsc/p increasing in a different frequency than the host
279 hosts support rdtscp, both guest rdtsc and rdtscp instructions will be