Commit 46a08e38 authored by Lennart Poettering's avatar Lennart Poettering
Browse files

readahead: disable readahead in virtual machines

parent a49728dc
......@@ -649,6 +649,11 @@ int main(int argc, char *argv[]) {
return 0;
}
if (running_in_vm()) {
log_info("Disabling readahead collector due to execution in virtual machine.");
return 0;
}
if (!(shared = shared_get()))
return 1;
......
......@@ -346,6 +346,11 @@ int main(int argc, char*argv[]) {
return 0;
}
if (running_in_vm()) {
log_info("Disabling readahead replay due to execution in virtual machine.");
return 0;
}
if (!(shared = shared_get()))
return 1;
......
......@@ -3564,6 +3564,82 @@ const char *default_term_for_tty(const char *tty) {
return "TERM=vt100";
}
bool running_in_vm(void) {
#if defined(__i386__) || defined(__x86_64__)
/* Both CPUID and DMI are x86 specific interfaces... */
const char *const dmi_vendors[] = {
"/sys/class/dmi/id/sys_vendor",
"/sys/class/dmi/id/board_vendor",
"/sys/class/dmi/id/bios_vendor"
};
uint32_t eax = 0x40000000;
union {
uint32_t sig32[3];
char text[13];
} sig;
unsigned i;
for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
char *s;
bool b;
if (read_one_line_file(dmi_vendors[i], &s) < 0)
continue;
b = startswith(s, "QEMU") ||
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
startswith(s, "VMware") ||
startswith(s, "VMW") ||
startswith(s, "Microsoft Corporation") ||
startswith(s, "innotek GmbH") ||
startswith(s, "Xen");
free(s);
if (b)
return true;
}
/* http://lwn.net/Articles/301888/ */
zero(sig);
#if defined (__i386__)
#define REG_a "eax"
#define REG_b "ebx"
#elif defined (__amd64__)
#define REG_a "rax"
#define REG_b "rbx"
#endif
__asm__ __volatile__ (
/* ebx/rbx is being used for PIC! */
" push %%"REG_b" \n\t"
" cpuid \n\t"
" mov %%ebx, %1 \n\t"
" pop %%"REG_b" \n\t"
: "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
: "0" (eax)
);
if (streq(sig.text, "XenVMMXenVMM") ||
streq(sig.text, "KVMKVMKVM") ||
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
streq(sig.text, "VMwareVMware") ||
/* http://msdn.microsoft.com/en-us/library/bb969719.aspx */
streq(sig.text, "Microsoft Hv"))
return true;
#endif
return false;
}
static const char *const ioprio_class_table[] = {
[IOPRIO_CLASS_NONE] = "none",
[IOPRIO_CLASS_RT] = "realtime",
......
......@@ -372,6 +372,8 @@ void filter_environ(const char *prefix);
const char *default_term_for_tty(const char *tty);
bool running_in_vm(void);
#define NULSTR_FOREACH(i, l) \
for ((i) = (l); (i) && *(i); (i) = strchr((i), 0)+1)
......
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