diff mbox series

[v6,13/13] NFS: Trace effects of the readdirplus heuristic

Message ID 20220221160851.15508-14-trondmy@kernel.org (mailing list archive)
State New, archived
Headers show
Series Readdir improvements | expand

Commit Message

Trond Myklebust Feb. 21, 2022, 4:08 p.m. UTC 
From: Trond Myklebust <trond.myklebust@hammerspace.com>

Enable tracking of when the readdirplus heuristic causes a page cache
invalidation.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
 fs/nfs/dir.c      |  6 +++++-
 fs/nfs/nfstrace.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index bcbfe03e3835..9f48c75dbf4c 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1141,7 +1141,11 @@  static void nfs_readdir_handle_cache_misses(struct inode *inode,
 	    cache_misses <= NFS_READDIR_CACHE_MISS_THRESHOLD ||
 	    !nfs_readdir_may_fill_pagecache(desc))
 		return;
-	invalidate_mapping_pages(inode->i_mapping, page_index + 1, -1);
+	if (invalidate_mapping_pages(inode->i_mapping, page_index + 1, -1) == 0)
+		return;
+	trace_nfs_readdir_invalidate_cache_range(
+		inode, (loff_t)(page_index + 1) << PAGE_SHIFT,
+		MAX_LFS_FILESIZE);
 }
 
 /* The file offset position represents the dirent entry number.  A
diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h
index 7c1102b991d0..ec2645d20abf 100644
--- a/fs/nfs/nfstrace.h
+++ b/fs/nfs/nfstrace.h
@@ -273,6 +273,56 @@  DEFINE_NFS_UPDATE_SIZE_EVENT(wcc);
 DEFINE_NFS_UPDATE_SIZE_EVENT(update);
 DEFINE_NFS_UPDATE_SIZE_EVENT(grow);
 
+DECLARE_EVENT_CLASS(nfs_inode_range_event,
+		TP_PROTO(
+			const struct inode *inode,
+			loff_t range_start,
+			loff_t range_end
+		),
+
+		TP_ARGS(inode, range_start, range_end),
+
+		TP_STRUCT__entry(
+			__field(dev_t, dev)
+			__field(u32, fhandle)
+			__field(u64, fileid)
+			__field(u64, version)
+			__field(loff_t, range_start)
+			__field(loff_t, range_end)
+		),
+
+		TP_fast_assign(
+			const struct nfs_inode *nfsi = NFS_I(inode);
+
+			__entry->dev = inode->i_sb->s_dev;
+			__entry->fhandle = nfs_fhandle_hash(&nfsi->fh);
+			__entry->fileid = nfsi->fileid;
+			__entry->version = inode_peek_iversion_raw(inode);
+			__entry->range_start = range_start;
+			__entry->range_end = range_end;
+		),
+
+		TP_printk(
+			"fileid=%02x:%02x:%llu fhandle=0x%08x version=%llu "
+			"range=[%lld, %lld]",
+			MAJOR(__entry->dev), MINOR(__entry->dev),
+			(unsigned long long)__entry->fileid,
+			__entry->fhandle, __entry->version,
+			__entry->range_start, __entry->range_end
+		)
+);
+
+#define DEFINE_NFS_INODE_RANGE_EVENT(name) \
+	DEFINE_EVENT(nfs_inode_range_event, name, \
+			TP_PROTO( \
+				const struct inode *inode, \
+				loff_t range_start, \
+				loff_t range_end \
+			), \
+			TP_ARGS(inode, range_start, range_end))
+
+DEFINE_NFS_INODE_RANGE_EVENT(nfs_readdir_invalidate_cache_range);
+
 DECLARE_EVENT_CLASS(nfs_readdir_event,
 		TP_PROTO(
 			const struct file *file,