On Tue, Aug 6, 2024 at 3:36 AM Zhiguo Jiang <justinjiang@xxxxxxxx> wrote:
>
> One of the main reasons for the prolonged exit of the process with
> independent mm is the time-consuming release of its swap entries.
> The proportion of swap memory occupied by the process increases over
> time due to high memory pressure triggering to reclaim anonymous folio
> into swapspace, e.g., in Android devices, we found this proportion can
> reach 60% or more after a period of time. Additionally, the relatively
> lengthy path for releasing swap entries further contributes to the
> longer time required to release swap entries.
>
> Testing Platform: 8GB RAM
> Testing procedure:
> After booting up, start 15 processes first, and then observe the
> physical memory size occupied by the last launched process at different
> time points.
> Example: The process launched last: com.qiyi.video
> | memory type | 0min | 1min | 5min | 10min | 15min |
> -------------------------------------------------------------------
> | VmRSS(KB) | 453832 | 252300 | 204364 | 199944 | 199748 |
> | RssAnon(KB) | 247348 | 99296 | 71268 | 67808 | 67660 |
> | RssFile(KB) | 205536 | 152020 | 132144 | 131184 | 131136 |
> | RssShmem(KB) | 1048 | 984 | 952 | 952 | 952 |
> | VmSwap(KB) | 202692 | 334852 | 362880 | 366340 | 366488 |
> | Swap ratio(%) | 30.87% | 57.03% | 63.97% | 64.69% | 64.72% |
> Note: min - minute.
>
> When there are multiple processes with independent mm and the high
> memory pressure in system, if the large memory required process is
> launched at this time, system will is likely to trigger the instantaneous
> killing of many processes with independent mm. Due to multiple exiting
> processes occupying multiple CPU core resources for concurrent execution,
> leading to some issues such as the current non-exiting and important
> processes lagging.
>
> To solve this problem, we have introduced the multiple exiting process
> asynchronous swap entries release mechanism, which isolates and caches
> swap entries occupied by multiple exiting processes, and hands them over
> to an asynchronous kworker to complete the release. This allows the
> exiting processes to complete quickly and release CPU resources. We have
> validated this modification on the Android products and achieved the
> expected benefits.
>
> Testing Platform: 8GB RAM
> Testing procedure:
> After restarting the machine, start 15 app processes first, and then
> start the camera app processes, we monitor the cold start and preview
> time datas of the camera app processes.
>
> Test datas of camera processes cold start time (unit: millisecond):
> | seq | 1 | 2 | 3 | 4 | 5 | 6 | average |
> | before | 1498 | 1476 | 1741 | 1337 | 1367 | 1655 | 1512 |
> | after | 1396 | 1107 | 1136 | 1178 | 1071 | 1339 | 1204 |
>
> Test datas of camera processes preview time (unit: millisecond):
> | seq | 1 | 2 | 3 | 4 | 5 | 6 | average |
> | before | 267 | 402 | 504 | 513 | 161 | 265 | 352 |
> | after | 188 | 223 | 301 | 203 | 162 | 154 | 205 |
>
> Base on the average of the six sets of test datas above, we can see that
> the benefit datas of the modified patch:
> 1. The cold start time of camera app processes has reduced by about 20%.
> 2. The preview time of camera app processes has reduced by about 42%.
>
> It offers several benefits:
> 1. Alleviate the high system cpu loading caused by multiple exiting
> processes running simultaneously.
> 2. Reduce lock competition in swap entry free path by an asynchronous
> kworker instead of multiple exiting processes parallel execution.
> 3. Release pte_present memory occupied by exiting processes more
> efficiently.
>
> Signed-off-by: Zhiguo Jiang <justinjiang@xxxxxxxx>
> ---
> arch/s390/include/asm/tlb.h | 8 +
> include/asm-generic/tlb.h | 44 ++++++
> include/linux/mm_types.h | 58 +++++++
> mm/memory.c | 3 +-
> mm/mmu_gather.c | 296 ++++++++++++++++++++++++++++++++++++
> 5 files changed, 408 insertions(+), 1 deletion(-)
>
> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
> index e95b2c8081eb..3f681f63390f
> --- a/arch/s390/include/asm/tlb.h
> +++ b/arch/s390/include/asm/tlb.h
> @@ -28,6 +28,8 @@ static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
> struct page *page, bool delay_rmap, int page_size);
> static inline bool __tlb_remove_folio_pages(struct mmu_gather *tlb,
> struct page *page, unsigned int nr_pages, bool delay_rmap);
> +static inline bool __tlb_remove_swap_entries(struct mmu_gather *tlb,
> + swp_entry_t entry, int nr);
>
> #define tlb_flush tlb_flush
> #define pte_free_tlb pte_free_tlb
> @@ -69,6 +71,12 @@ static inline bool __tlb_remove_folio_pages(struct mmu_gather *tlb,
> return false;
> }
>
> +static inline bool __tlb_remove_swap_entries(struct mmu_gather *tlb,
> + swp_entry_t entry, int nr)
> +{
> + return false;
> +}
> +
> static inline void tlb_flush(struct mmu_gather *tlb)
> {
> __tlb_flush_mm_lazy(tlb->mm);
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 709830274b75..8b4d516b35b8
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -294,6 +294,37 @@ extern void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma);
> static inline void tlb_flush_rmaps(struct mmu_gather *tlb, struct vm_area_struct *vma) { }
> #endif
>
> +#ifndef CONFIG_MMU_GATHER_NO_GATHER
> +struct mmu_swap_batch {
> + struct mmu_swap_batch *next;
> + unsigned int nr;
> + unsigned int max;
> + encoded_swpentry_t encoded_entrys[];
> +};
> +
> +#define MAX_SWAP_GATHER_BATCH \
> + ((PAGE_SIZE - sizeof(struct mmu_swap_batch)) / sizeof(void *))
> +
> +#define MAX_SWAP_GATHER_BATCH_COUNT (10000UL / MAX_SWAP_GATHER_BATCH)
> +
> +struct mmu_swap_gather {
> + /*
> + * the asynchronous kworker to batch
> + * release swap entries
> + */
> + struct work_struct free_work;
> +
> + /* batch cache swap entries */
> + unsigned int batch_count;
> + struct mmu_swap_batch *active;
> + struct mmu_swap_batch local;
> + encoded_swpentry_t __encoded_entrys[MMU_GATHER_BUNDLE];
> +};
> +
> +bool __tlb_remove_swap_entries(struct mmu_gather *tlb,
> + swp_entry_t entry, int nr);
> +#endif
> +
> /*
> * struct mmu_gather is an opaque type used by the mm code for passing around
> * any data needed by arch specific code for tlb_remove_page.
> @@ -343,6 +374,18 @@ struct mmu_gather {
> unsigned int vma_exec : 1;
> unsigned int vma_huge : 1;
> unsigned int vma_pfn : 1;
> +#ifndef CONFIG_MMU_GATHER_NO_GATHER
> + /*
> + * Two states of releasing swap entries
> + * asynchronously:
> + * swp_freeable - have opportunity to
> + * release asynchronously future
> + * swp_freeing - be releasing asynchronously.
> + */
> + unsigned int swp_freeable : 1;
> + unsigned int swp_freeing : 1;
> + unsigned int swp_disable : 1;
> +#endif
>
> unsigned int batch_count;
>
> @@ -354,6 +397,7 @@ struct mmu_gather {
> #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
> unsigned int page_size;
> #endif
> + struct mmu_swap_gather *swp;
> #endif
> };
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 165c58b12ccc..2f66303f1519
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -283,6 +283,64 @@ typedef struct {
> unsigned long val;
> } swp_entry_t;
>
> +/*
> + * encoded_swpentry_t - a type marking the encoded swp_entry_t.
> + *
> + * An 'encoded_swpentry_t' represents a 'swp_enrty_t' with its the highest
> + * bit indicating extra context-dependent information. Only used in swp_entry
> + * asynchronous release path by mmu_swap_gather.
> + */
> +typedef struct {
> + unsigned long val;
> +} encoded_swpentry_t;
> +
> +/*
> + * The next item in an encoded_swpentry_t array is the "nr" argument, specifying the
> + * total number of consecutive swap entries associated with the same folio. If this
> + * bit is not set, "nr" is implicitly 1.
> + *
> + * Refer to include\asm\pgtable.h, swp_offset bits: 0 ~ 57, swp_type bits: 58 ~ 62.
> + * Bit63 can be used here.
> + */
> +#define ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT (1UL << (BITS_PER_LONG - 1))
> +
> +static __always_inline encoded_swpentry_t
> +encode_swpentry(swp_entry_t entry, unsigned long flags)
> +{
> + encoded_swpentry_t ret;
> +
> + VM_WARN_ON_ONCE(flags & ~ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT);
> + ret.val = flags | entry.val;
> + return ret;
> +}
> +
> +static inline unsigned long encoded_swpentry_flags(encoded_swpentry_t entry)
> +{
> + return ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT & entry.val;
> +}
> +
> +static inline swp_entry_t encoded_swpentry_data(encoded_swpentry_t entry)
> +{
> + swp_entry_t ret;
> +
> + ret.val = ~ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT & entry.val;
> + return ret;
> +}
> +
> +static __always_inline encoded_swpentry_t encode_nr_swpentrys(unsigned long nr)
> +{
> + encoded_swpentry_t ret;
> +
> + VM_WARN_ON_ONCE(nr & ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT);
> + ret.val = nr;
> + return ret;
> +}
> +
> +static __always_inline unsigned long encoded_nr_swpentrys(encoded_swpentry_t entry)
> +{
> + return ((~ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT) & entry.val);
> +}
> +
> /**
> * struct folio - Represents a contiguous set of bytes.
> * @flags: Identical to the page flags.
> diff --git a/mm/memory.c b/mm/memory.c
> index d6a9dcddaca4..023a8adcb67c
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1650,7 +1650,8 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
> if (!should_zap_cows(details))
> continue;
> rss[MM_SWAPENTS] -= nr;
> - free_swap_and_cache_nr(entry, nr);
> + if (!__tlb_remove_swap_entries(tlb, entry, nr))
> + free_swap_and_cache_nr(entry, nr);
> } else if (is_migration_entry(entry)) {
> folio = pfn_swap_entry_folio(entry);
> if (!should_zap_folio(details, folio))
> diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
> index 99b3e9408aa0..33dc9d1faff9
> --- a/mm/mmu_gather.c
> +++ b/mm/mmu_gather.c
> @@ -9,11 +9,303 @@
> #include <linux/smp.h>
> #include <linux/swap.h>
> #include <linux/rmap.h>
> +#include <linux/oom.h>
>
> #include <asm/pgalloc.h>
> #include <asm/tlb.h>
>
> #ifndef CONFIG_MMU_GATHER_NO_GATHER
> +/*
> + * The swp_entry asynchronous release mechanism for multiple processes with
> + * independent mm exiting simultaneously.
> + *
> + * During the multiple exiting processes releasing their own mm simultaneously,
> + * the swap entries in the exiting processes are handled by isolating, caching
> + * and handing over to an asynchronous kworker to complete the release.
> + *
> + * The conditions for the exiting process entering the swp_entry asynchronous
> + * release path:
> + * 1. The exiting process's MM_SWAPENTS count is >= SWAP_CLUSTER_MAX, avoiding
> + * to alloc struct mmu_swap_gather frequently.
> + * 2. The number of exiting processes is >= NR_MIN_EXITING_PROCESSES.
Hi Zhiguo,
I'm curious about the significance of NR_MIN_EXITING_PROCESSES. It seems that
batched swap entry freeing, even with one process, could be a
bottleneck for a single
process based on the data from this patch:
mm: attempt to batch free swap entries for zap_pte_range()
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/commit/?h=mm-stable&id=bea67dcc5ee
"munmap bandwidth becomes 3X faster."
So what would happen if you simply set NR_MIN_EXITING_PROCESSES to 1?
> + *
> + * Since the time for determining the number of exiting processes is dynamic,
> + * the exiting process may start to enter the swp_entry asynchronous release
> + * at the beginning or middle stage of the exiting process's swp_entry release
> + * path.
> + *
> + * Once an exiting process enters the swp_entry asynchronous release, all remaining
> + * swap entries in this exiting process need to be fully released by asynchronous
> + * kworker theoretically.
Freeing a slot can indeed release memory from `zRAM`, potentially returning
it to the system for allocation. Your patch frees swap slots asynchronously;
I assume this doesn’t slow down the memory freeing process for `zRAM`, or
could it even slow down the freeing of `zRAM` memory? Freeing compressed
memory might not be as crucial compared to freeing uncompressed memory with
present PTEs?
> + *
> + * The function of the swp_entry asynchronous release:
> + * 1. Alleviate the high system cpu load caused by multiple exiting processes
> + * running simultaneously.
> + * 2. Reduce lock competition in swap entry free path by an asynchronous kworker
> + * instead of multiple exiting processes parallel execution.
> + * 3. Release pte_present memory occupied by exiting processes more efficiently.
> + */
> +
> +/*
> + * The min number of exiting processes required for swp_entry asynchronous release
> + */
> +#define NR_MIN_EXITING_PROCESSES 2
> +
> +static atomic_t nr_exiting_processes = ATOMIC_INIT(0);
> +static struct kmem_cache *swap_gather_cachep;
> +static struct workqueue_struct *swapfree_wq;
> +static DEFINE_STATIC_KEY_TRUE(tlb_swap_asyncfree_disabled);
> +
> +static int __init tlb_swap_async_free_setup(void)
> +{
> + swapfree_wq = alloc_workqueue("smfree_wq", WQ_UNBOUND |
> + WQ_HIGHPRI | WQ_MEM_RECLAIM, 1);
> + if (!swapfree_wq)
> + goto fail;
> +
> + swap_gather_cachep = kmem_cache_create("swap_gather",
> + sizeof(struct mmu_swap_gather),
> + 0, SLAB_TYPESAFE_BY_RCU | SLAB_PANIC | SLAB_ACCOUNT,
> + NULL);
> + if (!swap_gather_cachep)
> + goto kcache_fail;
> +
> + static_branch_disable(&tlb_swap_asyncfree_disabled);
> + return 0;
> +
> +kcache_fail:
> + destroy_workqueue(swapfree_wq);
> +fail:
> + return -ENOMEM;
> +}
> +postcore_initcall(tlb_swap_async_free_setup);
> +
> +static void __tlb_swap_gather_free(struct mmu_swap_gather *swap_gather)
> +{
> + struct mmu_swap_batch *swap_batch, *next;
> +
> + for (swap_batch = swap_gather->local.next; swap_batch; swap_batch = next) {
> + next = swap_batch->next;
> + free_page((unsigned long)swap_batch);
> + }
> + swap_gather->local.next = NULL;
> + kmem_cache_free(swap_gather_cachep, swap_gather);
> +}
> +
> +static void tlb_swap_async_free_work(struct work_struct *w)
> +{
> + int i, nr_multi, nr_free;
> + swp_entry_t start_entry;
> + struct mmu_swap_batch *swap_batch;
> + struct mmu_swap_gather *swap_gather = container_of(w,
> + struct mmu_swap_gather, free_work);
> +
> + /* Release swap entries cached in mmu_swap_batch. */
> + for (swap_batch = &swap_gather->local; swap_batch && swap_batch->nr;
> + swap_batch = swap_batch->next) {
> + nr_free = 0;
> + for (i = 0; i < swap_batch->nr; i++) {
> + if (unlikely(encoded_swpentry_flags(swap_batch->encoded_entrys[i]) &
> + ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT)) {
> + start_entry = encoded_swpentry_data(swap_batch->encoded_entrys[i]);
> + nr_multi = encoded_nr_swpentrys(swap_batch->encoded_entrys[++i]);
> + free_swap_and_cache_nr(start_entry, nr_multi);
> + nr_free += 2;
> + } else {
> + start_entry = encoded_swpentry_data(swap_batch->encoded_entrys[i]);
> + free_swap_and_cache_nr(start_entry, 1);
> + nr_free++;
> + }
> + }
> + swap_batch->nr -= nr_free;
> + VM_BUG_ON(swap_batch->nr);
> + }
> + __tlb_swap_gather_free(swap_gather);
> +}
> +
> +static bool __tlb_swap_gather_mmu_check(struct mmu_gather *tlb)
> +{
> + /*
> + * Only the exiting processes with the MM_SWAPENTS counter >=
> + * SWAP_CLUSTER_MAX have the opportunity to release their swap
> + * entries by asynchronous kworker.
> + */
> + if (!task_is_dying() ||
> + get_mm_counter(tlb->mm, MM_SWAPENTS) < SWAP_CLUSTER_MAX)
> + return true;
> +
> + atomic_inc(&nr_exiting_processes);
> + if (atomic_read(&nr_exiting_processes) < NR_MIN_EXITING_PROCESSES)
> + tlb->swp_freeable = 1;
> + else
> + tlb->swp_freeing = 1;
> +
> + return false;
> +}
> +
> +/**
> + * __tlb_swap_gather_init - Initialize an mmu_swap_gather structure
> + * for swp_entry tear-down.
> + * @tlb: the mmu_swap_gather structure belongs to tlb
> + */
> +static bool __tlb_swap_gather_init(struct mmu_gather *tlb)
> +{
> + tlb->swp = kmem_cache_alloc(swap_gather_cachep, GFP_ATOMIC | GFP_NOWAIT);
> + if (unlikely(!tlb->swp))
> + return false;
> +
> + tlb->swp->local.next = NULL;
> + tlb->swp->local.nr = 0;
> + tlb->swp->local.max = ARRAY_SIZE(tlb->swp->__encoded_entrys);
> +
> + tlb->swp->active = &tlb->swp->local;
> + tlb->swp->batch_count = 0;
> +
> + INIT_WORK(&tlb->swp->free_work, tlb_swap_async_free_work);
> + return true;
> +}
> +
> +static void __tlb_swap_gather_mmu(struct mmu_gather *tlb)
> +{
> + if (static_branch_unlikely(&tlb_swap_asyncfree_disabled))
> + return;
> +
> + tlb->swp = NULL;
> + tlb->swp_freeable = 0;
> + tlb->swp_freeing = 0;
> + tlb->swp_disable = 0;
> +
> + if (__tlb_swap_gather_mmu_check(tlb))
> + return;
> +
> + /*
> + * If the exiting process meets the conditions of
> + * swp_entry asynchronous release, an mmu_swap_gather
> + * structure will be initialized.
> + */
> + if (tlb->swp_freeing)
> + __tlb_swap_gather_init(tlb);
> +}
> +
> +static void __tlb_swap_gather_queuework(struct mmu_gather *tlb, bool finish)
> +{
> + queue_work(swapfree_wq, &tlb->swp->free_work);
> + tlb->swp = NULL;
> + if (!finish)
> + __tlb_swap_gather_init(tlb);
> +}
> +
> +static bool __tlb_swap_next_batch(struct mmu_gather *tlb)
> +{
> + struct mmu_swap_batch *swap_batch;
> +
> + if (tlb->swp->batch_count == MAX_SWAP_GATHER_BATCH_COUNT)
> + goto free;
> +
> + swap_batch = (void *)__get_free_page(GFP_ATOMIC | GFP_NOWAIT);
> + if (unlikely(!swap_batch))
> + goto free;
> +
> + swap_batch->next = NULL;
> + swap_batch->nr = 0;
> + swap_batch->max = MAX_SWAP_GATHER_BATCH;
> +
> + tlb->swp->active->next = swap_batch;
> + tlb->swp->active = swap_batch;
> + tlb->swp->batch_count++;
> + return true;
> +free:
> + /* batch move to wq */
> + __tlb_swap_gather_queuework(tlb, false);
> + return false;
> +}
> +
> +/**
> + * __tlb_remove_swap_entries - the swap entries in exiting process are
> + * isolated, batch cached in struct mmu_swap_batch.
> + * @tlb: the current mmu_gather
> + * @entry: swp_entry to be isolated and cached
> + * @nr: the number of consecutive entries starting from entry parameter.
> + */
> +bool __tlb_remove_swap_entries(struct mmu_gather *tlb,
> + swp_entry_t entry, int nr)
> +{
> + struct mmu_swap_batch *swap_batch;
> + unsigned long flags = 0;
> + bool ret = false;
> +
> + if (tlb->swp_disable)
> + return ret;
> +
> + if (!tlb->swp_freeable && !tlb->swp_freeing)
> + return ret;
> +
> + if (tlb->swp_freeable) {
> + if (atomic_read(&nr_exiting_processes) <
> + NR_MIN_EXITING_PROCESSES)
> + return ret;
> + /*
> + * If the current number of exiting processes
> + * is >= NR_MIN_EXITING_PROCESSES, the exiting
> + * process with swp_freeable state will enter
> + * swp_freeing state to start releasing its
> + * remaining swap entries by the asynchronous
> + * kworker.
> + */
> + tlb->swp_freeable = 0;
> + tlb->swp_freeing = 1;
> + }
> +
> + VM_BUG_ON(tlb->swp_freeable || !tlb->swp_freeing);
> + if (!tlb->swp && !__tlb_swap_gather_init(tlb))
> + return ret;
> +
> + swap_batch = tlb->swp->active;
> + if (unlikely(swap_batch->nr >= swap_batch->max - 1)) {
> + __tlb_swap_gather_queuework(tlb, false);
> + return ret;
> + }
> +
> + if (likely(nr == 1)) {
> + swap_batch->encoded_entrys[swap_batch->nr++] = encode_swpentry(entry, flags);
> + } else {
> + flags |= ENCODED_SWPENTRY_BIT_NR_ENTRYS_NEXT;
> + swap_batch->encoded_entrys[swap_batch->nr++] = encode_swpentry(entry, flags);
> + swap_batch->encoded_entrys[swap_batch->nr++] = encode_nr_swpentrys(nr);
> + }
> + ret = true;
> +
> + if (swap_batch->nr >= swap_batch->max - 1) {
> + if (!__tlb_swap_next_batch(tlb))
> + goto exit;
> + swap_batch = tlb->swp->active;
> + }
> + VM_BUG_ON(swap_batch->nr > swap_batch->max - 1);
> +exit:
> + return ret;
> +}
> +
> +static void __tlb_batch_swap_finish(struct mmu_gather *tlb)
> +{
> + if (tlb->swp_disable)
> + return;
> +
> + if (!tlb->swp_freeable && !tlb->swp_freeing)
> + return;
> +
> + if (tlb->swp_freeable) {
> + tlb->swp_freeable = 0;
> + VM_BUG_ON(tlb->swp_freeing);
> + goto exit;
> + }
> + tlb->swp_freeing = 0;
> + if (unlikely(!tlb->swp))
> + goto exit;
> +
> + __tlb_swap_gather_queuework(tlb, true);
> +exit:
> + atomic_dec(&nr_exiting_processes);
> +}
>
> static bool tlb_next_batch(struct mmu_gather *tlb)
> {
> @@ -386,6 +678,9 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
> tlb->local.max = ARRAY_SIZE(tlb->__pages);
> tlb->active = &tlb->local;
> tlb->batch_count = 0;
> +
> + tlb->swp_disable = 1;
> + __tlb_swap_gather_mmu(tlb);
> #endif
> tlb->delayed_rmap = 0;
>
> @@ -466,6 +761,7 @@ void tlb_finish_mmu(struct mmu_gather *tlb)
>
> #ifndef CONFIG_MMU_GATHER_NO_GATHER
> tlb_batch_list_free(tlb);
> + __tlb_batch_swap_finish(tlb);
> #endif
> dec_tlb_flush_pending(tlb->mm);
> }
> --
> 2.39.0
>
Thanks
Barry
