Messages in this thread | | | Date | Mon, 14 Oct 2013 11:57:38 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH 1/2] perf tools: avoid traverse dsos list while find vdso |
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Em Mon, Sep 09, 2013 at 09:21:55PM +0800, Chenggang Qin escreveu: > From: Chenggang Qin <chenggang.qcg@taobao.com> > > Vdso is only one in a system. It is not necessory to traverse the > macine->user_dsos list when looking for the dso of vdso. > The flag vdso_found should be replaced by a pointor that point to the dso of > vdso. If the pointer is NULL, dso of vdso have not been created. Else, the > pointor can be returned directly in function vdso__dso_findnew(). > The list traversing can be avoided by this method. > Thanks. > > Cc: David Ahern <dsahern@gmail.com> > Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> > Cc: Paul Mackerras <paulus@samba.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> > Cc: Arjan van de Ven <arjan@linux.intel.com> > Cc: Namhyung Kim <namhyung@gmail.com> > Cc: Yanmin Zhang <yanmin.zhang@intel.com> > Cc: Wu Fengguang <fengguang.wu@intel.com> > Cc: Mike Galbraith <efault@gmx.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Signed-off-by: Chenggang Qin <chenggang.qcg@taobao.com> > > --- > tools/perf/util/vdso.c | 22 ++++++++-------------- > 1 files changed, 8 insertions(+), 14 deletions(-) > > diff --git a/tools/perf/util/vdso.c b/tools/perf/util/vdso.c > index 3915982..8022ef0 100644 > --- a/tools/perf/util/vdso.c > +++ b/tools/perf/util/vdso.c > @@ -13,7 +13,7 @@ > #include "symbol.h" > #include "linux/string.h" > > -static bool vdso_found; > +static struct dso *vdso_dso = NULL; > static char vdso_file[] = "/tmp/perf-vdso.so-XXXXXX"; > > static int find_vdso_map(void **start, void **end) > @@ -55,9 +55,6 @@ static char *get_file(void) > size_t size; > int fd; > > - if (vdso_found) > - return vdso_file; > - > if (find_vdso_map(&start, &end)) > return NULL; > > @@ -79,33 +76,30 @@ static char *get_file(void) > out: > free(buf); > > - vdso_found = (vdso != NULL); > return vdso; > } > > void vdso__exit(void) > { > - if (vdso_found) > + if (vdso_dso) > unlink(vdso_file);
Don't we have to delete the vfso_dso and set it to NULL?
> } > > struct dso *vdso__dso_findnew(struct list_head *head) > { > - struct dso *dso = dsos__find(head, VDSO__MAP_NAME, true); > - > - if (!dso) { > + if (!vdso_dso) { > char *file; > > file = get_file(); > if (!file) > return NULL; > > - dso = dso__new(VDSO__MAP_NAME); > - if (dso != NULL) { > - dsos__add(head, dso); > - dso__set_long_name(dso, file); > + vdso_dso = dso__new(VDSO__MAP_NAME); > + if (vdso_dso != NULL) { > + dsos__add(head, vdso_dso); > + dso__set_long_name(vdso_dso, file); > } > } > > - return dso; > + return vdso_dso; > } > -- > 1.7.8.rc2.5.g815b
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