From: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Subject: dax: add tracepoints to dax_load_hole() 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@xxxxxxxxxxxxxxx Signed-off-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/dax.c | 16 +++++++++++----- include/trace/events/fs_dax.h | 1 + 2 files changed, 12 insertions(+), 5 deletions(-) diff -puN fs/dax.c~dax-add-tracepoints-to-dax_load_hole fs/dax.c --- a/fs/dax.c~dax-add-tracepoints-to-dax_load_hole +++ a/fs/dax.c @@ -509,21 +509,25 @@ int dax_invalidate_mapping_entry_sync(st 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_ 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; } diff -puN include/trace/events/fs_dax.h~dax-add-tracepoints-to-dax_load_hole include/trace/events/fs_dax.h --- a/include/trace/events/fs_dax.h~dax-add-tracepoints-to-dax_load_hole +++ a/include/trace/events/fs_dax.h @@ -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 */ _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
