mm, vmscan: remove ISOLATE_UNMAPPED

This isolate_mode_t flag is effectively unused since 89f6c88a6ab4 ("mm:
__isolate_lru_page_prepare() in isolate_migratepages_block()") as
sc->may_unmap is now checked directly (and only node_reclaim has a mode
that sets it to 0). The last remaining place is mm_vmscan_lru_isolate
tracepoint for the isolate_mode parameter. That one was mainly used to
indicate the active/inactive mode, which the trace-vmscan-postprocess.pl
script consumed, but that got silently broken. After fixing the script by
the previous patch, it does not need the isolate_mode anymore. So just
remove the parameter and with that the whole ISOLATE_UNMAPPED flag.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Vlastimil Babka <[e-mail]>
Cc: Hugh Dickins <[e-mail]>
Cc: Mel Gorman <[e-mail]>
Cc: Vlastimil Babka <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

Documentation/trace/postprocess/trace-vmscan-postprocess.pl

···
 my $regex_kswapd_wake_default = 'nid=([0-9]*) order=([0-9]*)';
 my $regex_kswapd_sleep_default = 'nid=([0-9]*)';
 my $regex_wakeup_kswapd_default = 'nid=([0-9]*) order=([0-9]*) gfp_flags=([A-Z_|]*)';
-my $regex_lru_isolate_default = 'isolate_mode=([0-9]*) classzone=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_skipped=([0-9]*) nr_taken=([0-9]*) lru=([a-z_]*)';
+my $regex_lru_isolate_default = 'classzone=([0-9]*) order=([0-9]*) nr_requested=([0-9]*) nr_scanned=([0-9]*) nr_skipped=([0-9]*) nr_taken=([0-9]*) lru=([a-z_]*)';
 my $regex_lru_shrink_inactive_default = 'nid=([0-9]*) nr_scanned=([0-9]*) nr_reclaimed=([0-9]*) nr_dirty=([0-9]*) nr_writeback=([0-9]*) nr_congested=([0-9]*) nr_immediate=([0-9]*) nr_activate_anon=([0-9]*) nr_activate_file=([0-9]*) nr_ref_keep=([0-9]*) nr_unmap_fail=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)';
 my $regex_lru_shrink_active_default = 'lru=([A-Z_]*) nr_taken=([0-9]*) nr_active=([0-9]*) nr_deactivated=([0-9]*) nr_referenced=([0-9]*) priority=([0-9]*) flags=([A-Z_|]*)' ;
 my $regex_writepage_default = 'page=([0-9a-f]*) pfn=([0-9]*) flags=([A-Z_|]*)';
···
 $regex_lru_isolate = generate_traceevent_regex(
 			"vmscan/mm_vmscan_lru_isolate",
 			$regex_lru_isolate_default,
-			"isolate_mode", classzone", "order",
+			"classzone", "order",
 			"nr_requested", "nr_scanned", "nr_skipped", "nr_taken",
 			"lru");
 $regex_lru_shrink_inactive = generate_traceevent_regex(
···
 				print "         $regex_lru_isolate/o\n";
 				next;
 			}
-			my $nr_scanned = $5;
-			my $lru = $8;
+			my $nr_scanned = $4;
+			my $lru = $7;
 
 			# To closer match vmstat scanning statistics, only count
 			# inactive lru as scanning

include/linux/mmzone.h

···
 #endif
 };
 
-/* Isolate unmapped pages */
-#define ISOLATE_UNMAPPED	((__force isolate_mode_t)0x2)
 /* Isolate for asynchronous migration */
 #define ISOLATE_ASYNC_MIGRATE	((__force isolate_mode_t)0x4)
 /* Isolate unevictable pages */

include/trace/events/vmscan.h

···
 		unsigned long nr_scanned,
 		unsigned long nr_skipped,
 		unsigned long nr_taken,
-		isolate_mode_t isolate_mode,
 		int lru),
 
-	TP_ARGS(highest_zoneidx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, isolate_mode, lru),
+	TP_ARGS(highest_zoneidx, order, nr_requested, nr_scanned, nr_skipped, nr_taken, lru),
 
 	TP_STRUCT__entry(
 		__field(int, highest_zoneidx)
···
 		__field(unsigned long, nr_scanned)
 		__field(unsigned long, nr_skipped)
 		__field(unsigned long, nr_taken)
-		__field(unsigned int, isolate_mode)
 		__field(int, lru)
 	),
 
···
 		__entry->nr_scanned = nr_scanned;
 		__entry->nr_skipped = nr_skipped;
 		__entry->nr_taken = nr_taken;
-		__entry->isolate_mode = (__force unsigned int)isolate_mode;
 		__entry->lru = lru;
 	),
 
···
 	 * classzone is previous name of the highest_zoneidx.
 	 * Reason not to change it is the ABI requirement of the tracepoint.
 	 */
-	TP_printk("isolate_mode=%d classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_skipped=%lu nr_taken=%lu lru=%s",
-		__entry->isolate_mode,
+	TP_printk("classzone=%d order=%d nr_requested=%lu nr_scanned=%lu nr_skipped=%lu nr_taken=%lu lru=%s",
 		__entry->highest_zoneidx,
 		__entry->order,
 		__entry->nr_requested,

mm/vmscan.c

···
 	}
 	*nr_scanned = total_scan;
 	trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
-				    total_scan, skipped, nr_taken,
-				    sc->may_unmap ? 0 : ISOLATE_UNMAPPED, lru);
+				    total_scan, skipped, nr_taken, lru);
 	update_lru_sizes(lruvec, lru, nr_zone_taken);
 	return nr_taken;
 }