Lines Matching refs:rdtsc
21 Does the OS/app use the rdtsc instruction at all?
26 At what frequency is the rdtsc instruction executed by either the OS
27 or any running apps? If the sum exceeds about 10,000 rdtsc instructions
34 If the OS/app does use rdtsc, will it behave incorrectly if "time goes
43 that uses rdtsc must be assumed to be TSC-sensitive and, as we
47 the family of rdtsc instructions are executed "natively" vs emulated.
48 Roughly speaking, native means rdtsc is fast but TSC-sensitive apps
52 all rdtsc instructions were native: "fast but potentially incorrect."
53 Starting at Xen 4.0, the default is that all rdtsc instructions are
56 how rdtsc instructions are executed differently for different domains.
64 All rdtsc instructions are emulated; this is the best choice when
107 To determine the frequency of rdtsc instructions that are emulated,
181 The rdtsc (read timestamp counter) instruction is used to read the
182 TSC register. The rdtscp instruction is a variant of rdtsc on recent
183 processors. We refer to these together as the rdtsc family of instructions,
184 or just "rdtsc". Instructions in the rdtsc family are non-privileged, but
185 privileged software may set a cpuid bit to cause all rdtsc family
187 then transparently "emulate" the results of the rdtsc instruction and
188 return control to the code following the rdtsc instruction.
191 fixed rate, Xen provides rdtsc emulation whenever necessary or when
193 relatively slow -- roughly 15-20 times slower than the rdtsc instruction
195 the rdtsc instruction at a high frequency (e.g. more than about 10,000 times
205 TSC-safe, rdtsc will execute at hardware speed; if it is not, rdtsc
219 on top of Xen), and utilizes a variation of the rdtsc instruction
221 (The rdtscp instruction differs from the rdtsc instruction in that it
300 emulating an rdtsc.
331 fast as a native rdtsc instruction, much faster than emulation,
340 by guest rdtsc/p increasing in a different frequency than the host
351 hosts support rdtscp, both guest rdtsc and rdtscp instructions will be