Skip to content

chore(port): port boot performance improvements to 6.18-lts #28

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
kaniini merged 2 commits into from
Oct 15, 2026
Merged

chore(port): port boot performance improvements to 6.18-lts #28

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
23a1a45
x86/xen: take the early CPU frequency from the hypervisor
azenla Aug 22, 2026
5fa9fe1
xen/xenbus: wake the boot device wait when a backend changes state
azenla Aug 22, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions arch/x86/xen/time.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -567,6 +567,7 @@ static void __init xen_init_time_common(void)
paravirt_set_sched_clock(xen_sched_clock);

x86_platform.calibrate_tsc = xen_tsc_khz;
x86_platform.calibrate_cpu = xen_tsc_khz;
x86_platform.get_wallclock = xen_get_wallclock;
}

Expand Down
30 changes: 24 additions & 6 deletions drivers/xen/xenbus/xenbus_probe_frontend.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -85,10 +85,17 @@ static int xenbus_uevent_frontend(const struct device *_dev,
}


/* Condition for wait_for_devices(): bumped on every backend state change. */
static atomic_t frontend_wait_seq = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(frontend_wait_wq);

static void backend_changed(struct xenbus_watch *watch,
const char *path, const char *token)
{
xenbus_otherend_changed(watch, path, token, 1);

atomic_inc(&frontend_wait_seq);
wake_up(&frontend_wait_wq);
}

static void xenbus_frontend_delayed_resume(struct work_struct *w)
Expand Down Expand Up @@ -265,7 +272,7 @@ static int print_device_status(struct device *dev, void *data)
static int ready_to_wait_for_devices;

static bool wait_loop(unsigned long start, unsigned int max_delay,
unsigned int *seconds_waited)
unsigned int *seconds_waited, unsigned int seq)
{
if (time_after(jiffies, start + (*seconds_waited+5)*HZ)) {
if (!*seconds_waited)
Expand All @@ -278,7 +285,8 @@ static bool wait_loop(unsigned long start, unsigned int max_delay,
}
}

schedule_timeout_interruptible(HZ/10);
wait_event_interruptible_timeout(frontend_wait_wq,
atomic_read(&frontend_wait_seq) != seq, HZ/10);

return false;
}
Expand All @@ -301,18 +309,28 @@ static void wait_for_devices(struct xenbus_driver *xendrv)
unsigned long start = jiffies;
struct device_driver *drv = xendrv ? &xendrv->driver : NULL;
unsigned int seconds_waited = 0;
unsigned int seq;

if (!ready_to_wait_for_devices || !xen_domain())
return;

while (exists_non_essential_connecting_device(drv))
if (wait_loop(start, 30, &seconds_waited))
/* Sample the sequence before checking, so a change in between wakes us. */
for (;;) {
seq = atomic_read(&frontend_wait_seq);
if (!exists_non_essential_connecting_device(drv))
break;
if (wait_loop(start, 30, &seconds_waited, seq))
break;
}

/* Skips PVKB and PVFB check.*/
while (exists_essential_connecting_device(drv))
if (wait_loop(start, 270, &seconds_waited))
for (;;) {
seq = atomic_read(&frontend_wait_seq);
if (!exists_essential_connecting_device(drv))
break;
if (wait_loop(start, 270, &seconds_waited, seq))
break;
}

if (seconds_waited)
printk("\n");
Expand Down