On 2/11/2026 9:22 AM, Dmitry Ilvokhin wrote:
> Compaction uses compact_lock_irqsave(), which currently operates
> on a raw spinlock_t pointer so that it can be used for both
> zone->lock and lru_lock. Since zone lock operations are now wrapped,
> compact_lock_irqsave() can no longer operate directly on a spinlock_t
> when the lock belongs to a zone.
>
> Introduce struct compact_lock to abstract the underlying lock type. The
> structure carries a lock type enum and a union holding either a zone
> pointer or a raw spinlock_t pointer, and dispatches to the appropriate
> lock/unlock helper.
>
> No functional change intended.
>
> Signed-off-by: Dmitry Ilvokhin <[email protected]>
> ---
> mm/compaction.c | 108 +++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 89 insertions(+), 19 deletions(-)
>
> diff --git a/mm/compaction.c b/mm/compaction.c
> index 1e8f8eca318c..1b000d2b95b2 100644
> --- a/mm/compaction.c
> +++ b/mm/compaction.c
> @@ -24,6 +24,7 @@
> #include <linux/page_owner.h>
> #include <linux/psi.h>
> #include <linux/cpuset.h>
> +#include <linux/zone_lock.h>
> #include "internal.h"
>
> #ifdef CONFIG_COMPACTION
> @@ -493,6 +494,65 @@ static bool test_and_set_skip(struct compact_control
> *cc, struct page *page)
> }
> #endif /* CONFIG_COMPACTION */
>
> +enum compact_lock_type {
> + COMPACT_LOCK_ZONE,
> + COMPACT_LOCK_RAW_SPINLOCK,
> +};
> +
> +struct compact_lock {
> + enum compact_lock_type type;
> + union {
> + struct zone *zone;
> + spinlock_t *lock; /* Reference to lru lock */
> + };
> +};
> +
> +static bool compact_do_zone_trylock_irqsave(struct zone *zone,
> + unsigned long *flags)
> +{
> + return zone_trylock_irqsave(zone, *flags);
> +}
> +
> +static bool compact_do_raw_trylock_irqsave(spinlock_t *lock,
> + unsigned long *flags)
> +{
> + return spin_trylock_irqsave(lock, *flags);
> +}
> +
> +static bool compact_do_trylock_irqsave(struct compact_lock lock,
> + unsigned long *flags)
> +{
> + if (lock.type == COMPACT_LOCK_ZONE)
> + return compact_do_zone_trylock_irqsave(lock.zone, flags);
> +
> + return compact_do_raw_trylock_irqsave(lock.lock, flags);
> +}
Nit: You could remove the helpers above and just do the calls directly in this
function, though
it would remove the parity with the compact helpers. compact_do_lock_irqsave()
helpers can stay
since they have the __acquires() annotations.
> +
> +static void compact_do_zone_lock_irqsave(struct zone *zone,
> + unsigned long *flags)
> +__acquires(zone->lock)
> +{
> + zone_lock_irqsave(zone, *flags);
> +}
> +
> +static void compact_do_raw_lock_irqsave(spinlock_t *lock,
> + unsigned long *flags)
> +__acquires(lock)
> +{
> + spin_lock_irqsave(lock, *flags);
> +}
> +
> +static void compact_do_lock_irqsave(struct compact_lock lock,
> + unsigned long *flags)
> +{
> + if (lock.type == COMPACT_LOCK_ZONE) {
> + compact_do_zone_lock_irqsave(lock.zone, flags);
> + return;
> + }
> +
> + return compact_do_raw_lock_irqsave(lock.lock, flags);
You don't need the return statement here (and you shouldn't be returning a
value at all).
It may be cleaner to just do an if-else statement here instead.
> +}
> +
> /*
> * Compaction requires the taking of some coarse locks that are potentially
> * very heavily contended. For async compaction, trylock and record if the
> @@ -502,19 +562,19 @@ static bool test_and_set_skip(struct compact_control
> *cc, struct page *page)
> *
> * Always returns true which makes it easier to track lock state in callers.
> */
> -static bool compact_lock_irqsave(spinlock_t *lock, unsigned long *flags,
> - struct compact_control *cc)
> - __acquires(lock)
> +static bool compact_lock_irqsave(struct compact_lock lock,
> + unsigned long *flags,
> + struct compact_control *cc)
> {
> /* Track if the lock is contended in async mode */
> if (cc->mode == MIGRATE_ASYNC && !cc->contended) {
> - if (spin_trylock_irqsave(lock, *flags))
> + if (compact_do_trylock_irqsave(lock, flags))
> return true;
>
> cc->contended = true;
> }
>
> - spin_lock_irqsave(lock, *flags);
> + compact_do_lock_irqsave(lock, flags);
> return true;
> }
>
> @@ -530,11 +590,13 @@ static bool compact_lock_irqsave(spinlock_t *lock,
> unsigned long *flags,
> * Returns true if compaction should abort due to fatal signal pending.
> * Returns false when compaction can continue.
> */
> -static bool compact_unlock_should_abort(spinlock_t *lock,
> - unsigned long flags, bool *locked, struct compact_control *cc)
> +static bool compact_unlock_should_abort(struct zone *zone,
> + unsigned long flags,
> + bool *locked,
> + struct compact_control *cc)
> {
> if (*locked) {
> - spin_unlock_irqrestore(lock, flags);
> + zone_unlock_irqrestore(zone, flags);
I would move this (and other wrapper changes below that don't use compact_*) to
the last patch. I understand you
didn't change it due to location but I would argue it isn't really relevant to
what's being added in this patch
and fits better in the last.
> *locked = false;
> }
>
> @@ -582,9 +644,8 @@ static unsigned long isolate_freepages_block(struct
> compact_control *cc,
> * contention, to give chance to IRQs. Abort if fatal signal
> * pending.
> */
> - if (!(blockpfn % COMPACT_CLUSTER_MAX)
> - && compact_unlock_should_abort(&cc->zone->lock, flags,
> - &locked, cc))
> + if (!(blockpfn % COMPACT_CLUSTER_MAX) &&
> + compact_unlock_should_abort(cc->zone, flags, &locked, cc))
> break;
>
> nr_scanned++;
> @@ -613,8 +674,12 @@ static unsigned long isolate_freepages_block(struct
> compact_control *cc,
>
> /* If we already hold the lock, we can skip some rechecking. */
> if (!locked) {
> - locked = compact_lock_irqsave(&cc->zone->lock,
> - &flags, cc);
> + struct compact_lock zol = {
> + .type = COMPACT_LOCK_ZONE,
> + .zone = cc->zone,
> + };
> +
> + locked = compact_lock_irqsave(zol, &flags, cc);
>
> /* Recheck this is a buddy page under lock */
> if (!PageBuddy(page))
> @@ -649,7 +714,7 @@ static unsigned long isolate_freepages_block(struct
> compact_control *cc,
> }
>
> if (locked)
> - spin_unlock_irqrestore(&cc->zone->lock, flags);
> + zone_unlock_irqrestore(cc->zone, flags);
>
> /*
> * Be careful to not go outside of the pageblock.
> @@ -1157,10 +1222,15 @@ isolate_migratepages_block(struct compact_control
> *cc, unsigned long low_pfn,
>
> /* If we already hold the lock, we can skip some rechecking */
> if (lruvec != locked) {
> + struct compact_lock zol = {
> + .type = COMPACT_LOCK_RAW_SPINLOCK,
> + .lock = &lruvec->lru_lock,
> + };
> +
> if (locked)
> unlock_page_lruvec_irqrestore(locked, flags);
>
> - compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
> + compact_lock_irqsave(zol, &flags, cc);
> locked = lruvec;
>
> lruvec_memcg_debug(lruvec, folio);
> @@ -1555,7 +1625,7 @@ static void fast_isolate_freepages(struct
> compact_control *cc)
> if (!area->nr_free)
> continue;
>
> - spin_lock_irqsave(&cc->zone->lock, flags);
> + zone_lock_irqsave(cc->zone, flags);
> freelist = &area->free_list[MIGRATE_MOVABLE];
> list_for_each_entry_reverse(freepage, freelist, buddy_list) {
> unsigned long pfn;
> @@ -1614,7 +1684,7 @@ static void fast_isolate_freepages(struct
> compact_control *cc)
> }
> }
>
> - spin_unlock_irqrestore(&cc->zone->lock, flags);
> + zone_unlock_irqrestore(cc->zone, flags);
>
> /* Skip fast search if enough freepages isolated */
> if (cc->nr_freepages >= cc->nr_migratepages)
> @@ -1988,7 +2058,7 @@ static unsigned long fast_find_migrateblock(struct
> compact_control *cc)
> if (!area->nr_free)
> continue;
>
> - spin_lock_irqsave(&cc->zone->lock, flags);
> + zone_lock_irqsave(cc->zone, flags);
> freelist = &area->free_list[MIGRATE_MOVABLE];
> list_for_each_entry(freepage, freelist, buddy_list) {
> unsigned long free_pfn;
> @@ -2021,7 +2091,7 @@ static unsigned long fast_find_migrateblock(struct
> compact_control *cc)
> break;
> }
> }
> - spin_unlock_irqrestore(&cc->zone->lock, flags);
> + zone_unlock_irqrestore(cc->zone, flags);
> }
>
> cc->total_migrate_scanned += nr_scanned;
