ANDROID: mm: add a new vendor hook in filemap_map_pages

In the current vendor hook, if next_uptodate_folio returns NULL, the
first_pgoff is set to zero, and the last_pgoff is set to start_pgoff.
Therefore, the collection range is from 0 to the start_pgoff.

|-----------|------------|-------------|------------------|
0      start_pgoff  first_pgoff    last_pgoff         end_pgoff

We want to collect the first_pgoff to last_pgoff, so we have to add a
new vendor hook.

Bug: 397274634
Change-Id: I19d54c601e2ffc5de5ec2dafcd43fbdcdc84b0d2
Signed-off-by: zhanghui <[email protected]>

Author: zhanghui31

drivers/android/vendor_hooks.c

@@ -641,3 +641,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_typec_tcpm_modify_src_caps);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_typec_tcpm_log);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_proactive_compact_wmark_high);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_trigger_vendor_lmk_kill);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_filemap_map_pages_range);

include/trace/hooks/mm.h

@@ -523,6 +523,10 @@ DECLARE_HOOK(android_vh_page_private_mod,
 DECLARE_HOOK(android_vh_cma_alloc_fail,
 	TP_PROTO(char *name, unsigned long count, unsigned long req_count),
 	TP_ARGS(name, count, req_count));
+DECLARE_HOOK(android_vh_filemap_map_pages_range,
+	TP_PROTO(struct file *file, pgoff_t orig_start_pgoff,
+		pgoff_t last_pgoff, vm_fault_t ret),
+	TP_ARGS(file, orig_start_pgoff, last_pgoff, ret));
 #endif /* _TRACE_HOOK_MM_H */
 
 /* This part must be outside protection */

mm/filemap.c

@@ -3687,12 +3687,14 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
 	vm_fault_t ret = 0;
 	unsigned int nr_pages = 0, mmap_miss = 0, mmap_miss_saved;
 	pgoff_t first_pgoff = 0;
+	pgoff_t orig_start_pgoff = start_pgoff;
 
 	rcu_read_lock();
 	folio = next_uptodate_folio(&xas, mapping, end_pgoff);
 	if (!folio)
 		goto out;
 	first_pgoff = xas.xa_index;
+	orig_start_pgoff = xas.xa_index;
 
 	if (filemap_map_pmd(vmf, folio, start_pgoff)) {
 		ret = VM_FAULT_NOPAGE;
@@ -3736,6 +3738,7 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
 	else
 		WRITE_ONCE(file->f_ra.mmap_miss, mmap_miss_saved - mmap_miss);
 	trace_android_vh_filemap_map_pages(file, first_pgoff, last_pgoff, ret);
+	trace_android_vh_filemap_map_pages_range(file, orig_start_pgoff, last_pgoff, ret);
 
 	return ret;
 }