From: Minchan Kim <minchan@google.com>
Date: Sun, 12 Aug 2018 23:15:32 +0000 (+0900)
Subject: mm: mm_event: add read io stat
X-Git-Tag: MMI-RSBS31.Q1-48-36-26~79
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a42ad457105266a3cb76b38028d950c2124fc627;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

mm: mm_event: add read io stat

Read IO's latency as well as filemap fault could affect system
performance so this patch keeps track it on.

Mot-CRs-fixed: (CR)

Bug: 80168800
Change-Id: I761b7110339cf1e5ef24530ad32aedd784d00d07
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
Reviewed-on: https://gerrit.mot.com/1453725
Tested-by: Jira Key
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
---

diff --git a/include/linux/mm_event.h b/include/linux/mm_event.h
index 81d9a72b11db..4d6fe7f2c97c 100644
--- a/include/linux/mm_event.h
+++ b/include/linux/mm_event.h
@@ -8,6 +8,7 @@
 enum mm_event_type {
 	MM_MIN_FAULT = 0,
 	MM_MAJ_FAULT,
+	MM_READ_IO,
 	MM_COMPACTION,
 	MM_RECLAIM,
 	MM_SWP_FAULT,
diff --git a/include/trace/events/mm_event.h b/include/trace/events/mm_event.h
index 7d69e42bc8bd..6073701d900c 100644
--- a/include/trace/events/mm_event.h
+++ b/include/trace/events/mm_event.h
@@ -14,6 +14,7 @@ struct mm_event_task;
 	__print_symbolic(type,                                          \
 	{ MM_MIN_FAULT, "min_flt" },                                    \
 	{ MM_MAJ_FAULT, "maj_flt" },                                    \
+	{ MM_READ_IO,	"read_io" },                                    \
 	{ MM_COMPACTION, "compaction" },                                \
 	{ MM_RECLAIM, "reclaim" },					\
 	{ MM_SWP_FAULT, "swp_flt" },					\
diff --git a/mm/filemap.c b/mm/filemap.c
index dff99a346d67..6a7bbb09d1b5 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1980,7 +1980,9 @@ static ssize_t generic_file_buffered_read(struct kiocb *iocb,
 		pgoff_t end_index;
 		loff_t isize;
 		unsigned long nr, ret;
+		ktime_t event_ts;
 
+		event_ts = 0;
 		cond_resched();
 find_page:
 		if (fatal_signal_pending(current)) {
@@ -1992,6 +1994,7 @@ find_page:
 		if (!page) {
 			if (iocb->ki_flags & IOCB_NOWAIT)
 				goto would_block;
+			mm_event_start(&event_ts);
 			page_cache_sync_readahead(mapping,
 					ra, filp,
 					index, last_index - index);
@@ -2038,6 +2041,8 @@ find_page:
 			unlock_page(page);
 		}
 page_ok:
+		if (event_ts != 0)
+			mm_event_end(MM_READ_IO, event_ts);
 		/*
 		 * i_size must be checked after we know the page is Uptodate.
 		 *