Messages in this thread Patch in this message | | | Date | Fri, 20 Oct 2023 15:50:30 -0700 (PDT) | From | Ilkka Koskinen <> | Subject | Re: [PATCH 2/3] perf/arm-cmn: Rework DTC counters (again) |
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Hi Robin,
I have one comment, otherwise the patch looks good to me.
On Fri, 20 Oct 2023, Robin Murphy wrote: > The bitmap-based scheme for tracking DTC counter usage turns out to be a > complete dead-end for its imagined purpose, since by the time we have to > keep track of a per-DTC counter index anyway, we already have enough > information to make the bitmap itself redundant. Revert the remains of > it back to almost the original scheme, but now expanded to track per-DTC > indices, in preparation for making use of them in anger. > > Note that since cycle count events always use a dedicated counter on a > single DTC, we reuse the field to encode their DTC index directly. > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > drivers/perf/arm-cmn.c | 126 +++++++++++++++++++++-------------------- > 1 file changed, 64 insertions(+), 62 deletions(-) > > diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c > index f1ac8d0cdb3b..675f1638013e 100644 > --- a/drivers/perf/arm-cmn.c > +++ b/drivers/perf/arm-cmn.c > @@ -281,16 +281,13 @@ struct arm_cmn_node { > u16 id, logid; > enum cmn_node_type type; >
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> @@ -589,8 +586,7 @@ static void arm_cmn_debugfs_init(struct arm_cmn *cmn, int id) {} > struct arm_cmn_hw_event { > struct arm_cmn_node *dn; > u64 dtm_idx[4]; > - unsigned int dtc_idx; > - u8 dtcs_used; > + s8 dtc_idx[CMN_MAX_DTCS]; > u8 num_dns; > u8 dtm_offset; > bool wide_sel; > @@ -600,6 +596,10 @@ struct arm_cmn_hw_event { > #define for_each_hw_dn(hw, dn, i) \ > for (i = 0, dn = hw->dn; i < hw->num_dns; i++, dn++) > > +/* @i is the DTC number, @idx is the counter index on that DTC */ > +#define for_each_hw_dtc_idx(hw, i, idx) \ > + for (int i = 0, idx; i < CMN_MAX_DTCS; i++) if ((idx = hw->dtc_idx[i]) >= 0)
Isn't that "idx" unnecessary in the initialization?
Cheers, Ilkka
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