linux-kernel - Re: [PATCH 1/2] perf:tools: avoid to create much more maps for kernel symbols on ARM

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Message-ID: <20101124144540.GB15875@ghostprotocols.net>
Date:	Wed, 24 Nov 2010 12:45:40 -0200
From:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
To:	tom.leiming@...il.com
Cc:	linux-kernel@...r.kernel.org, Ian Munsie <imunsie@....ibm.com>,
	Ingo Molnar <mingo@...e.hu>, Paul Mackerras <paulus@...ba.org>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tom Zanussi <tzanussi@...il.com>
Subject: Re: [PATCH 1/2] perf:tools: avoid to create much more maps for
 kernel symbols on ARM

Em Wed, Nov 24, 2010 at 07:35:02PM +0800, tom.leiming@...il.com escreveu:
> From: Ming Lei <tom.leiming@...il.com>
 
> On ARM, module addresss space is ahead of kernel space, so the module
> symbols are handled before kernel symbol in dso__split_kallsyms, then
> cause one map is created for each kernel symbol.
 
> This patch fixes the issue by restoring to original kernel map in
> dso__split_kallsyms() to avoid create unnecessary maps for kernel
> symbols when starting to handle kenel symbol maps but after module
> symbol maps are handled over.

Can you try with the following patch instead?

- Arnaldo

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index b39f499..a7518d2 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -530,7 +530,7 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
 	struct machine *machine = kmaps->machine;
 	struct map *curr_map = map;
 	struct symbol *pos;
-	int count = 0;
+	int count = 0, moved = 0;	
 	struct rb_root *root = &self->symbols[map->type];
 	struct rb_node *next = rb_first(root);
 	int kernel_range = 0;
@@ -588,6 +588,11 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
 			char dso_name[PATH_MAX];
 			struct dso *dso;
 
+			if (count == 0) {
+				curr_map = map;
+				goto filter_symbol;
+			}
+
 			if (self->kernel == DSO_TYPE_GUEST_KERNEL)
 				snprintf(dso_name, sizeof(dso_name),
 					"[guest.kernel].%d",
@@ -613,7 +618,7 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
 			map_groups__insert(kmaps, curr_map);
 			++kernel_range;
 		}
-
+filter_symbol:
 		if (filter && filter(curr_map, pos)) {
 discard_symbol:		rb_erase(&pos->rb_node, root);
 			symbol__delete(pos);
@@ -621,8 +626,9 @@ discard_symbol:		rb_erase(&pos->rb_node, root);
 			if (curr_map != map) {
 				rb_erase(&pos->rb_node, root);
 				symbols__insert(&curr_map->dso->symbols[curr_map->type], pos);
-			}
-			count++;
+				++moved;
+			} else
+				++count;
 		}
 	}
 
@@ -632,7 +638,7 @@ discard_symbol:		rb_erase(&pos->rb_node, root);
 		dso__set_loaded(curr_map->dso, curr_map->type);
 	}
 
-	return count;
+	return count + moved;
 }
 
 int dso__load_kallsyms(struct dso *self, const char *filename,
--
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