| Message ID | 20240311135230.7007-12-ilpo.jarvinen@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests/resctrl: resctrl_val() related cleanups & improvements | expand |
Hi Ilpo, On 3/11/2024 6:52 AM, Ilpo Järvinen wrote: > The struct resctrl_val_param has control and monitor groups as char > arrays but they are not supposed to be mutated within resctrl_val(). > > Convert the ctrlgrp and mongrp char array within resctrl_val_param to > plain const char pointers and adjust the strlen() based checks to > check NULL instead. > > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> > --- > tools/testing/selftests/resctrl/resctrl.h | 4 ++-- > tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++---- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h > index 52769b075233..54e5bce4c698 100644 > --- a/tools/testing/selftests/resctrl/resctrl.h > +++ b/tools/testing/selftests/resctrl/resctrl.h > @@ -89,8 +89,8 @@ struct resctrl_test { > */ > struct resctrl_val_param { > char *resctrl_val; > - char ctrlgrp[64]; > - char mongrp[64]; > + const char *ctrlgrp; > + const char *mongrp; > char filename[64]; > unsigned long mask; > int num_of_runs; > diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c > index 79cf1c593106..dbe0cc6d74fa 100644 > --- a/tools/testing/selftests/resctrl/resctrlfs.c > +++ b/tools/testing/selftests/resctrl/resctrlfs.c > @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp) > * length of grp_name == 0, it means, user wants to use root con_mon > * grp, so do nothing > */ Could you please confirm that the comments are still accurate? > - if (strlen(grp_name) == 0) > + if (!grp_name) > return 0; > Reinette
On Wed, 20 Mar 2024, Reinette Chatre wrote: > On 3/11/2024 6:52 AM, Ilpo Järvinen wrote: > > The struct resctrl_val_param has control and monitor groups as char > > arrays but they are not supposed to be mutated within resctrl_val(). > > > > Convert the ctrlgrp and mongrp char array within resctrl_val_param to > > plain const char pointers and adjust the strlen() based checks to > > check NULL instead. > > > > Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> > > --- > > tools/testing/selftests/resctrl/resctrl.h | 4 ++-- > > tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++---- > > 2 files changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h > > index 52769b075233..54e5bce4c698 100644 > > --- a/tools/testing/selftests/resctrl/resctrl.h > > +++ b/tools/testing/selftests/resctrl/resctrl.h > > @@ -89,8 +89,8 @@ struct resctrl_test { > > */ > > struct resctrl_val_param { > > char *resctrl_val; > > - char ctrlgrp[64]; > > - char mongrp[64]; > > + const char *ctrlgrp; > > + const char *mongrp; > > char filename[64]; > > unsigned long mask; > > int num_of_runs; > > diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c > > index 79cf1c593106..dbe0cc6d74fa 100644 > > --- a/tools/testing/selftests/resctrl/resctrlfs.c > > +++ b/tools/testing/selftests/resctrl/resctrlfs.c > > @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp) > > * length of grp_name == 0, it means, user wants to use root con_mon > > * grp, so do nothing > > */ > > Could you please confirm that the comments are still accurate? It's not, I missed it. > > - if (strlen(grp_name) == 0) > > + if (!grp_name) > > return 0; But now when looking into the surrounding code, to me it looks the correct action here is to remove the comment and return -1 instead of 0. It makes this just an internal sanity check that grp_name is provided by the caller.
Hi Ilpo, On 3/22/2024 5:30 AM, Ilpo Järvinen wrote: > On Wed, 20 Mar 2024, Reinette Chatre wrote: >> On 3/11/2024 6:52 AM, Ilpo Järvinen wrote: >>> The struct resctrl_val_param has control and monitor groups as char >>> arrays but they are not supposed to be mutated within resctrl_val(). >>> >>> Convert the ctrlgrp and mongrp char array within resctrl_val_param to >>> plain const char pointers and adjust the strlen() based checks to >>> check NULL instead. >>> >>> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> >>> --- >>> tools/testing/selftests/resctrl/resctrl.h | 4 ++-- >>> tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++---- >>> 2 files changed, 6 insertions(+), 6 deletions(-) >>> >>> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h >>> index 52769b075233..54e5bce4c698 100644 >>> --- a/tools/testing/selftests/resctrl/resctrl.h >>> +++ b/tools/testing/selftests/resctrl/resctrl.h >>> @@ -89,8 +89,8 @@ struct resctrl_test { >>> */ >>> struct resctrl_val_param { >>> char *resctrl_val; >>> - char ctrlgrp[64]; >>> - char mongrp[64]; >>> + const char *ctrlgrp; >>> + const char *mongrp; >>> char filename[64]; >>> unsigned long mask; >>> int num_of_runs; >>> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c >>> index 79cf1c593106..dbe0cc6d74fa 100644 >>> --- a/tools/testing/selftests/resctrl/resctrlfs.c >>> +++ b/tools/testing/selftests/resctrl/resctrlfs.c >>> @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp) >>> * length of grp_name == 0, it means, user wants to use root con_mon >>> * grp, so do nothing >>> */ >> >> Could you please confirm that the comments are still accurate? > > It's not, I missed it. > >>> - if (strlen(grp_name) == 0) >>> + if (!grp_name) >>> return 0; > > But now when looking into the surrounding code, to me it looks the correct > action here is to remove the comment and return -1 instead of 0. It makes > this just an internal sanity check that grp_name is provided by the > caller. > hmmm ... this should not be an error because the caller is not required to provide grp_name. Not providing grp_name has a specific meaning of this operating on the CON_MON group and a failure would break flows operating on the CON_MON group. Reinette
On Fri, 22 Mar 2024, Reinette Chatre wrote: > On 3/22/2024 5:30 AM, Ilpo Järvinen wrote: > > On Wed, 20 Mar 2024, Reinette Chatre wrote: > >> On 3/11/2024 6:52 AM, Ilpo Järvinen wrote: > >>> The struct resctrl_val_param has control and monitor groups as char > >>> arrays but they are not supposed to be mutated within resctrl_val(). > >>> > >>> Convert the ctrlgrp and mongrp char array within resctrl_val_param to > >>> plain const char pointers and adjust the strlen() based checks to > >>> check NULL instead. > >>> > >>> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> > >>> --- > >>> tools/testing/selftests/resctrl/resctrl.h | 4 ++-- > >>> tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++---- > >>> 2 files changed, 6 insertions(+), 6 deletions(-) > >>> > >>> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h > >>> index 52769b075233..54e5bce4c698 100644 > >>> --- a/tools/testing/selftests/resctrl/resctrl.h > >>> +++ b/tools/testing/selftests/resctrl/resctrl.h > >>> @@ -89,8 +89,8 @@ struct resctrl_test { > >>> */ > >>> struct resctrl_val_param { > >>> char *resctrl_val; > >>> - char ctrlgrp[64]; > >>> - char mongrp[64]; > >>> + const char *ctrlgrp; > >>> + const char *mongrp; > >>> char filename[64]; > >>> unsigned long mask; > >>> int num_of_runs; > >>> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c > >>> index 79cf1c593106..dbe0cc6d74fa 100644 > >>> --- a/tools/testing/selftests/resctrl/resctrlfs.c > >>> +++ b/tools/testing/selftests/resctrl/resctrlfs.c > >>> @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp) > >>> * length of grp_name == 0, it means, user wants to use root con_mon > >>> * grp, so do nothing > >>> */ > >> > >> Could you please confirm that the comments are still accurate? > > > > It's not, I missed it. > > > >>> - if (strlen(grp_name) == 0) > >>> + if (!grp_name) > >>> return 0; > > > > But now when looking into the surrounding code, to me it looks the correct > > action here is to remove the comment and return -1 instead of 0. It makes > > this just an internal sanity check that grp_name is provided by the > > caller. > > > > hmmm ... this should not be an error because the caller is not required > to provide grp_name. Not providing grp_name has a specific meaning > of this operating on the CON_MON group and a failure would break flows > operating on the CON_MON group. write_bm_pid_to_resctrl() checks for non-NULL mongrp before it calls into create_grp() so with current code, I don't think it changes anything. And param->ctrlgrp is always non-NULL too so I don't think the return ever triggers with the current codebase. However, I was more talking from API point of view. It feels more natural for "create group" function to return error if the caller is inconsistent with itself by asking to create a group but doesn't want to create a group.
diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h index 52769b075233..54e5bce4c698 100644 --- a/tools/testing/selftests/resctrl/resctrl.h +++ b/tools/testing/selftests/resctrl/resctrl.h @@ -89,8 +89,8 @@ struct resctrl_test { */ struct resctrl_val_param { char *resctrl_val; - char ctrlgrp[64]; - char mongrp[64]; + const char *ctrlgrp; + const char *mongrp; char filename[64]; unsigned long mask; int num_of_runs; diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 79cf1c593106..dbe0cc6d74fa 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -469,7 +469,7 @@ static int create_grp(const char *grp_name, char *grp, const char *parent_grp) * length of grp_name == 0, it means, user wants to use root con_mon * grp, so do nothing */ - if (strlen(grp_name) == 0) + if (!grp_name) return 0; /* Check if requested grp exists or not */ @@ -541,7 +541,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp, char tasks[1024]; int ret = 0; - if (strlen(ctrlgrp)) + if (ctrlgrp) sprintf(controlgroup, "%s/%s", RESCTRL_PATH, ctrlgrp); else sprintf(controlgroup, "%s", RESCTRL_PATH); @@ -558,7 +558,7 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp, /* Create mon grp and write pid into it for "mbm" and "cmt" test */ if (!strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)) || !strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR))) { - if (strlen(mongrp)) { + if (mongrp) { sprintf(monitorgroup_p, "%s/mon_groups", controlgroup); sprintf(monitorgroup, "%s/%s", monitorgroup_p, mongrp); ret = create_grp(mongrp, monitorgroup, monitorgroup_p); @@ -612,7 +612,7 @@ int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no, goto out; } - if (strlen(ctrlgrp) != 0) + if (ctrlgrp) sprintf(controlgroup, "%s/%s/schemata", RESCTRL_PATH, ctrlgrp); else sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
The struct resctrl_val_param has control and monitor groups as char arrays but they are not supposed to be mutated within resctrl_val(). Convert the ctrlgrp and mongrp char array within resctrl_val_param to plain const char pointers and adjust the strlen() based checks to check NULL instead. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> --- tools/testing/selftests/resctrl/resctrl.h | 4 ++-- tools/testing/selftests/resctrl/resctrlfs.c | 8 ++++---- 2 files changed, 6 insertions(+), 6 deletions(-)