From: Minchan Kim <minchan@google.com>
Date: Mon, 6 Aug 2018 06:07:57 +0000 (+0900)
Subject: mm: mm_event: add swapin stat
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1fb0a84213764813d80d2dffd494c09814c65b02;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

mm: mm_event: add swapin stat

Many embedded devices use zram as swap. Compared to storage swap
(e.g. UFS), swapin from zram(ie., decompression) is extremly fast
so it might be not major fault but minor. So this patch provides
swapin latency tracking to distinguish them from storage major
fault.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I1c32430e32a051916ede5219bd5f40a9002652bc
Signed-off-by: Minchan Kim <minchan@google.com>
Reviewed-on: https://gerrit.mot.com/1453723
Tested-by: Jira Key
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
---

diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index 6a9520698944..a1404ae4a12d 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -510,7 +510,10 @@ retry:
 			tsk->maj_flt++;
 			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, regs,
 				      addr);
-			mm_event_end(MM_MAJ_FAULT, event_ts);
+			if (fault & VM_FAULT_SWAP)
+				mm_event_end(MM_SWP_FAULT, event_ts);
+			else
+				mm_event_end(MM_MAJ_FAULT, event_ts);
 		} else {
 			tsk->min_flt++;
 			perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, regs,
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5c96d4395948..b14ca733a2b9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1177,6 +1177,7 @@ static inline void clear_page_pfmemalloc(struct page *page)
 #define VM_FAULT_HWPOISON 0x0010	/* Hit poisoned small page */
 #define VM_FAULT_HWPOISON_LARGE 0x0020  /* Hit poisoned large page. Index encoded in upper bits */
 #define VM_FAULT_SIGSEGV 0x0040
+#define VM_FAULT_SWAP 0x0080
 
 #define VM_FAULT_NOPAGE	0x0100	/* ->fault installed the pte, not return page */
 #define VM_FAULT_LOCKED	0x0200	/* ->fault locked the returned page */
diff --git a/include/linux/mm_event.h b/include/linux/mm_event.h
index 5a9069ea0fa7..2778fa09c650 100644
--- a/include/linux/mm_event.h
+++ b/include/linux/mm_event.h
@@ -10,6 +10,7 @@ enum mm_event_type {
 	MM_MAJ_FAULT,
 	MM_COMPACTION,
 	MM_RECLAIM,
+	MM_SWP_FAULT,
 	MM_TYPE_NUM,
 };
 
diff --git a/include/trace/events/mm_event.h b/include/trace/events/mm_event.h
index f43dee51f46f..34e6d55f0266 100644
--- a/include/trace/events/mm_event.h
+++ b/include/trace/events/mm_event.h
@@ -15,7 +15,8 @@ struct mm_event_task;
 	{ MM_MIN_FAULT, "min_flt" },                                    \
 	{ MM_MAJ_FAULT, "maj_flt" },                                    \
 	{ MM_COMPACTION, "compaction" },                                \
-	{ MM_RECLAIM, "reclaim" })
+	{ MM_RECLAIM, "reclaim" },					\
+	{ MM_SWP_FAULT, "swp_flt" })
 
 TRACE_EVENT(mm_event_record,
 
diff --git a/mm/memory.c b/mm/memory.c
index fb9f7737c1ff..16956844e553 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3052,7 +3052,7 @@ int do_swap_page(struct vm_fault *vmf)
 unlock:
 	pte_unmap_unlock(vmf->pte, vmf->ptl);
 out:
-	return ret;
+	return ret | VM_FAULT_SWAP;
 out_nomap:
 	mem_cgroup_cancel_charge(page, memcg, false);
 	pte_unmap_unlock(vmf->pte, vmf->ptl);
@@ -3064,7 +3064,7 @@ out_release:
 		unlock_page(swapcache);
 		put_page(swapcache);
 	}
-	return ret;
+	return ret | VM_FAULT_SWAP;
 }
 
 /*