dax: add tracepoints to dax_load_hole() (678c9fd0) · Commits · 戴 / test

Add tracepoints to dax_load_hole(), following the same logging conventions as the rest of DAX. Here is the logging generated by a PTE read from a hole: read-1075 [002] .... 62.362108: dax_pte_fault: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 read-1075 [002] .... 62.362140: dax_load_hole: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE read-1075 [002] .... 62.362141: dax_pte_fault_done: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE Link: http://lkml.kernel.org/r/20170221195116.13278-4-ross.zwisler@linux.intel.com Signed-off-by:

Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by:

Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/dax.c

+11 −5

Original line number	Diff line number	Diff line
		@@ -509,21 +509,25 @@ int dax_invalidate_mapping_entry_sync(struct address_space *mapping,
		static int dax_load_hole(struct address_space mapping, void *entry,
		struct vm_fault *vmf)
		{
		struct inode *inode = mapping->host;
		struct page *page;
		int ret;

		/* Hole page already exists? Return it... */
		if (!radix_tree_exceptional_entry(*entry)) {
		page = *entry;
		goto out;
		goto finish_fault;
		}

		/* This will replace locked radix tree entry with a hole page */
		page = find_or_create_page(mapping, vmf->pgoff,
		vmf->gfp_mask \| __GFP_ZERO);
		if (!page)
		return VM_FAULT_OOM;
		out:
		if (!page) {
		ret = VM_FAULT_OOM;
		goto out;
		}

		finish_fault:
		vmf->page = page;
		ret = finish_fault(vmf);
		vmf->page = NULL;
		@@ -531,8 +535,10 @@ static int dax_load_hole(struct address_space mapping, void *entry,
		if (!ret) {
		/* Grab reference for PTE that is now referencing the page */
		get_page(page);
		return VM_FAULT_NOPAGE;
		ret = VM_FAULT_NOPAGE;
		}
		out:
		trace_dax_load_hole(inode, vmf, ret);
		return ret;
		}

include/trace/events/fs_dax.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -192,6 +192,7 @@ DEFINE_PTE_FAULT_EVENT(dax_pte_fault);
		DEFINE_PTE_FAULT_EVENT(dax_pte_fault_done);
		DEFINE_PTE_FAULT_EVENT(dax_pfn_mkwrite_no_entry);
		DEFINE_PTE_FAULT_EVENT(dax_pfn_mkwrite);
		DEFINE_PTE_FAULT_EVENT(dax_load_hole);

		#endif /* _TRACE_FS_DAX_H */

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