lkml.org 
[lkml]   [2017]   [Oct]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] perf callchain: Compare dsos (as well) for CCKEY_FUNCTION
    Hi,

    On Thu, Oct 05, 2017 at 09:20:21AM +0530, Ravi Bangoria wrote:
    > Two functions from different binaries can have same start
    > address. Thus, comparing only start address in match_chain()
    > leads to inconsistent callchains. Fix this by adding a check
    > for dsos as well.
    >
    > Ex, https://www.spinics.net/lists/linux-perf-users/msg04067.html
    >
    > Reported-by: Alexander Pozdneev <pozdneyev@gmail.com>
    > Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
    > ---
    > tools/perf/util/callchain.c | 9 ++++++++-
    > 1 file changed, 8 insertions(+), 1 deletion(-)
    >
    > diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c
    > index be09d77..6d7f645 100644
    > --- a/tools/perf/util/callchain.c
    > +++ b/tools/perf/util/callchain.c
    > @@ -685,6 +685,9 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
    > {
    > struct symbol *sym = node->sym;
    > u64 left, right;
    > + struct dso *left_dso = NULL;
    > + struct dso *right_dso = NULL;
    > +
    >
    > if (callchain_param.key == CCKEY_SRCLINE) {
    > enum match_result match = match_chain_srcline(node, cnode);
    > @@ -696,12 +699,16 @@ static enum match_result match_chain(struct callchain_cursor_node *node,
    > if (cnode->ms.sym && sym && callchain_param.key == CCKEY_FUNCTION) {
    > left = cnode->ms.sym->start;
    > right = sym->start;
    > + if (cnode->ms.map)
    > + left_dso = cnode->ms.map->dso;
    > + if (node->map)
    > + right_dso = node->map->dso;

    AFAIK having a symbol guarantees having a map too. So it could simply
    be:

    left_dso = cnode->ms.map->dso;
    right_dso = node->map->dso;

    Thanks,
    Namhyung


    > } else {
    > left = cnode->ip;
    > right = node->ip;
    > }
    >
    > - if (left == right) {
    > + if (left == right && left_dso == right_dso) {
    > if (node->branch) {
    > cnode->branch_count++;
    >
    > --
    > 1.8.3.1
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html

    \
     
     \ /
      Last update: 2017-10-05 06:16    [W:2.498 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site