| Message ID | 167564540422.847146.13816934143225777888.stgit@dwillia2-xfh.jf.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | CXL RAM and the 'Soft Reserved' => 'System RAM' default | expand |
On Sun, Feb 05, 2023 at 05:03:24PM -0800, Dan Williams wrote: > A passthrough decoder is a decoder that maps only 1 target. It is a > special case because it does not impose any constraints on the > interleave-math as compared to a decoder with multiple targets. Extend > the passthrough case to multi-target-capable decoders that only have one > target selected. I.e. the current code was only considering passthrough > *ports* which are only a subset of the potential passthrough decoder > scenarios. > > Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") > Cc: <stable@vger.kernel.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> If a patch really is a "fix" that needs to go to stable kernels, why is it commit 10 out of 18? Why isn't it going to Linus now for inclusion in 6.2-final? Does it depend on the 9 earlier patches in this series? thanks, greg k-h
Greg KH wrote: > On Sun, Feb 05, 2023 at 05:03:24PM -0800, Dan Williams wrote: > > A passthrough decoder is a decoder that maps only 1 target. It is a > > special case because it does not impose any constraints on the > > interleave-math as compared to a decoder with multiple targets. Extend > > the passthrough case to multi-target-capable decoders that only have one > > target selected. I.e. the current code was only considering passthrough > > *ports* which are only a subset of the potential passthrough decoder > > scenarios. > > > > Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") > > Cc: <stable@vger.kernel.org> > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > If a patch really is a "fix" that needs to go to stable kernels, why is > it commit 10 out of 18? Why isn't it going to Linus now for inclusion > in 6.2-final? Does it depend on the 9 earlier patches in this series? In this case the urgency is low since the only environment known to produce this configuration is QEMU. However, there's now a more important CXL fix pending for this week, so this one can tag along.
On 2/5/23 6:03 PM, Dan Williams wrote: > A passthrough decoder is a decoder that maps only 1 target. It is a > special case because it does not impose any constraints on the > interleave-math as compared to a decoder with multiple targets. Extend > the passthrough case to multi-target-capable decoders that only have one > target selected. I.e. the current code was only considering passthrough > *ports* which are only a subset of the potential passthrough decoder > scenarios. > > Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") > Cc: <stable@vger.kernel.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/cxl/core/region.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index c82d3b6f3d1f..34cf95217901 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -1019,10 +1019,10 @@ static int cxl_port_setup_targets(struct cxl_port *port, > int i, distance; > > /* > - * Passthrough ports impose no distance requirements between > + * Passthrough decoders impose no distance requirements between > * peers > */ > - if (port->nr_dports == 1) > + if (cxl_rr->nr_targets == 1) > distance = 0; > else > distance = p->nr_targets / cxl_rr->nr_targets; >
On Sun, 05 Feb 2023 17:03:24 -0800 Dan Williams <dan.j.williams@intel.com> wrote: > A passthrough decoder is a decoder that maps only 1 target. It is a > special case because it does not impose any constraints on the > interleave-math as compared to a decoder with multiple targets. Extend > the passthrough case to multi-target-capable decoders that only have one > target selected. I.e. the current code was only considering passthrough > *ports* which are only a subset of the potential passthrough decoder > scenarios. > > Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") > Cc: <stable@vger.kernel.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/cxl/core/region.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index c82d3b6f3d1f..34cf95217901 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -1019,10 +1019,10 @@ static int cxl_port_setup_targets(struct cxl_port *port, > int i, distance; > > /* > - * Passthrough ports impose no distance requirements between > + * Passthrough decoders impose no distance requirements between > * peers I think we have a terminology inconsistency. My understanding was we were using passthrough decoders for the special case where there is no programmable hardware. In this case I think we are also considering the case where that hardware must be programmed etc, it's just that we don't care about interleave. I'd just explain what it is rather than trying to assign a term. Decoders that have a single target configured impose... > */ > - if (port->nr_dports == 1) > + if (cxl_rr->nr_targets == 1) > distance = 0; > else > distance = p->nr_targets / cxl_rr->nr_targets; > >
On Sun, 2023-02-05 at 17:03 -0800, Dan Williams wrote: > A passthrough decoder is a decoder that maps only 1 target. It is a > special case because it does not impose any constraints on the > interleave-math as compared to a decoder with multiple targets. Extend > the passthrough case to multi-target-capable decoders that only have one > target selected. I.e. the current code was only considering passthrough > *ports* which are only a subset of the potential passthrough decoder > scenarios. > > Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") > Cc: <stable@vger.kernel.org> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/cxl/core/region.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Looks good, Reviewed-by: Vishal Verma <vishal.l.verma@intel.com> > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index c82d3b6f3d1f..34cf95217901 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -1019,10 +1019,10 @@ static int cxl_port_setup_targets(struct cxl_port *port, > int i, distance; > > /* > - * Passthrough ports impose no distance requirements between > + * Passthrough decoders impose no distance requirements between > * peers > */ > - if (port->nr_dports == 1) > + if (cxl_rr->nr_targets == 1) > distance = 0; > else > distance = p->nr_targets / cxl_rr->nr_targets; > >
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index c82d3b6f3d1f..34cf95217901 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1019,10 +1019,10 @@ static int cxl_port_setup_targets(struct cxl_port *port, int i, distance; /* - * Passthrough ports impose no distance requirements between + * Passthrough decoders impose no distance requirements between * peers */ - if (port->nr_dports == 1) + if (cxl_rr->nr_targets == 1) distance = 0; else distance = p->nr_targets / cxl_rr->nr_targets;
A passthrough decoder is a decoder that maps only 1 target. It is a special case because it does not impose any constraints on the interleave-math as compared to a decoder with multiple targets. Extend the passthrough case to multi-target-capable decoders that only have one target selected. I.e. the current code was only considering passthrough *ports* which are only a subset of the potential passthrough decoder scenarios. Fixes: e4f6dfa9ef75 ("cxl/region: Fix 'distance' calculation with passthrough ports") Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/cxl/core/region.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)