diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | include/trace/events/ksm.h | 251 | ||||
| -rw-r--r-- | mm/ksm.c | 21 |
3 files changed, 271 insertions, 2 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 1dc8bd26b6cf..a62ffb710b47 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13409,6 +13409,7 @@ F: include/linux/memory_hotplug.h F: include/linux/mm.h F: include/linux/mmzone.h F: include/linux/pagewalk.h +F: include/trace/events/ksm.h F: mm/ F: tools/mm/ F: tools/testing/selftests/mm/ diff --git a/include/trace/events/ksm.h b/include/trace/events/ksm.h new file mode 100644 index 000000000000..b5ac35c1d0e8 --- /dev/null +++ b/include/trace/events/ksm.h @@ -0,0 +1,251 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM ksm + +#if !defined(_TRACE_KSM_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_KSM_H + +#include <linux/tracepoint.h> + +/** + * ksm_scan_template - called for start / stop scan + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the start / stop of a ksm scan. + */ +DECLARE_EVENT_CLASS(ksm_scan_template, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries), + + TP_STRUCT__entry( + __field(int, seq) + __field(u32, rmap_entries) + ), + + TP_fast_assign( + __entry->seq = seq; + __entry->rmap_entries = rmap_entries; + ), + + TP_printk("seq %d rmap size %d", + __entry->seq, __entry->rmap_entries) +); + +/** + * ksm_start_scan - called after a new ksm scan is started + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the start of a ksm scan. + */ +DEFINE_EVENT(ksm_scan_template, ksm_start_scan, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries) +); + +/** + * ksm_stop_scan - called after a new ksm scan has completed + * + * @seq: sequence number of scan + * @rmap_entries: actual number of rmap entries + * + * Allows to trace the completion of a ksm scan. + */ +DEFINE_EVENT(ksm_scan_template, ksm_stop_scan, + + TP_PROTO(int seq, u32 rmap_entries), + + TP_ARGS(seq, rmap_entries) +); + +/** + * ksm_enter - called after a new process has been added / removed from ksm + * + * @mm: address of the mm object of the process + * + * Allows to trace the when a process has been added or removed from ksm. + */ +DECLARE_EVENT_CLASS(ksm_enter_exit_template, + + TP_PROTO(void *mm), + + TP_ARGS(mm), + + TP_STRUCT__entry( + __field(void *, mm) + ), + + TP_fast_assign( + __entry->mm = mm; + ), + + TP_printk("mm %p", __entry->mm) +); + +/** + * ksm_enter - called after a new process has been added to ksm + * + * @mm: address of the mm object of the process + * + * Allows to trace the when a process has been added to ksm. + */ +DEFINE_EVENT(ksm_enter_exit_template, ksm_enter, + + TP_PROTO(void *mm), + + TP_ARGS(mm) +); + +/** + * ksm_exit - called after a new process has been removed from ksm + * + * @mm: address of the mm object of the process + * + * Allows to trace the when a process has been removed from ksm. + */ +DEFINE_EVENT(ksm_enter_exit_template, ksm_exit, + + TP_PROTO(void *mm), + + TP_ARGS(mm) +); + +/** + * ksm_merge_one_page - called after a page has been merged + * + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the process mm struct + * @err: success + * + * Allows to trace the ksm merging of individual pages. + */ +TRACE_EVENT(ksm_merge_one_page, + + TP_PROTO(unsigned long pfn, void *rmap_item, void *mm, int err), + + TP_ARGS(pfn, rmap_item, mm, err), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + __field(int, err) + ), + + TP_fast_assign( + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + __entry->err = err; + ), + + TP_printk("ksm pfn %lu rmap_item %p mm %p error %d", + __entry->pfn, __entry->rmap_item, __entry->mm, __entry->err) +); + +/** + * ksm_merge_with_ksm_page - called after a page has been merged with a ksm page + * + * @ksm_page: address ksm page + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the mm object of the process + * @err: success + * + * Allows to trace the merging of a page with a ksm page. + */ +TRACE_EVENT(ksm_merge_with_ksm_page, + + TP_PROTO(void *ksm_page, unsigned long pfn, void *rmap_item, void *mm, int err), + + TP_ARGS(ksm_page, pfn, rmap_item, mm, err), + + TP_STRUCT__entry( + __field(void *, ksm_page) + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + __field(int, err) + ), + + TP_fast_assign( + __entry->ksm_page = ksm_page; + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + __entry->err = err; + ), + + TP_printk("%spfn %lu rmap_item %p mm %p error %d", + (__entry->ksm_page ? "ksm " : ""), + __entry->pfn, __entry->rmap_item, __entry->mm, __entry->err) +); + +/** + * ksm_remove_ksm_page - called after a ksm page has been removed + * + * @pfn: page frame number of ksm page + * + * Allows to trace the removing of stable ksm pages. + */ +TRACE_EVENT(ksm_remove_ksm_page, + + TP_PROTO(unsigned long pfn), + + TP_ARGS(pfn), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + ), + + TP_fast_assign( + __entry->pfn = pfn; + ), + + TP_printk("pfn %lu", __entry->pfn) +); + +/** + * ksm_remove_rmap_item - called after a rmap_item has been removed from the + * stable tree + * + * @pfn: page frame number of ksm page + * @rmap_item: address of rmap_item object + * @mm: address of the process mm struct + * + * Allows to trace the removal of pages from the stable tree list. + */ +TRACE_EVENT(ksm_remove_rmap_item, + + TP_PROTO(unsigned long pfn, void *rmap_item, void *mm), + + TP_ARGS(pfn, rmap_item, mm), + + TP_STRUCT__entry( + __field(unsigned long, pfn) + __field(void *, rmap_item) + __field(void *, mm) + ), + + TP_fast_assign( + __entry->pfn = pfn; + __entry->rmap_item = rmap_item; + __entry->mm = mm; + ), + + TP_printk("pfn %lu rmap_item %p mm %p", + __entry->pfn, __entry->rmap_item, __entry->mm) +); + +#endif /* _TRACE_KSM_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> @@ -45,6 +45,9 @@ #include "internal.h" #include "mm_slot.h" +#define CREATE_TRACE_POINTS +#include <trace/events/ksm.h> + #ifdef CONFIG_NUMA #define NUMA(x) (x) #define DO_NUMA(x) do { (x); } while (0) @@ -633,10 +636,12 @@ static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node) BUG_ON(stable_node->rmap_hlist_len < 0); hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) { - if (rmap_item->hlist.next) + if (rmap_item->hlist.next) { ksm_pages_sharing--; - else + trace_ksm_remove_rmap_item(stable_node->kpfn, rmap_item, rmap_item->mm); + } else { ksm_pages_shared--; + } rmap_item->mm->ksm_merging_pages--; @@ -657,6 +662,7 @@ static void remove_node_from_stable_tree(struct ksm_stable_node *stable_node) BUILD_BUG_ON(STABLE_NODE_DUP_HEAD <= &migrate_nodes); BUILD_BUG_ON(STABLE_NODE_DUP_HEAD >= &migrate_nodes + 1); + trace_ksm_remove_ksm_page(stable_node->kpfn); if (stable_node->head == &migrate_nodes) list_del(&stable_node->list); else @@ -1324,6 +1330,8 @@ static int try_to_merge_with_ksm_page(struct ksm_rmap_item *rmap_item, get_anon_vma(vma->anon_vma); out: mmap_read_unlock(mm); + trace_ksm_merge_with_ksm_page(kpage, page_to_pfn(kpage ? kpage : page), + rmap_item, mm, err); return err; } @@ -2142,6 +2150,9 @@ static void cmp_and_merge_page(struct page *page, struct ksm_rmap_item *rmap_ite if (vma) { err = try_to_merge_one_page(vma, page, ZERO_PAGE(rmap_item->address)); + trace_ksm_merge_one_page( + page_to_pfn(ZERO_PAGE(rmap_item->address)), + rmap_item, mm, err); } else { /* * If the vma is out of date, we do not need to @@ -2264,6 +2275,8 @@ static struct ksm_rmap_item *scan_get_next_rmap_item(struct page **page) mm_slot = ksm_scan.mm_slot; if (mm_slot == &ksm_mm_head) { + trace_ksm_start_scan(ksm_scan.seqnr, ksm_rmap_items); + /* * A number of pages can hang around indefinitely on per-cpu * pagevecs, raised page count preventing write_protect_page @@ -2414,6 +2427,7 @@ no_vmas: if (mm_slot != &ksm_mm_head) goto next_mm; + trace_ksm_stop_scan(ksm_scan.seqnr, ksm_rmap_items); ksm_scan.seqnr++; return NULL; } @@ -2565,6 +2579,7 @@ int __ksm_enter(struct mm_struct *mm) if (needs_wakeup) wake_up_interruptible(&ksm_thread_wait); + trace_ksm_enter(mm); return 0; } @@ -2606,6 +2621,8 @@ void __ksm_exit(struct mm_struct *mm) mmap_write_lock(mm); mmap_write_unlock(mm); } + + trace_ksm_exit(mm); } struct page *ksm_might_need_to_copy(struct page *page, |