On Tue, Jun 24, 2025 at 03:40:16PM +0200, Jan Beulich wrote: > On 20.06.2025 13:11, Roger Pau Monne wrote: > > Introduce a command line option to allow disabling PDX compression. The > > disabling is done by turning pfn_pdx_add_region() into a no-op, so when > > attempting to initialize the selected compression algorithm the array of > > ranges to compress is empty. > > While neat, this also feels fragile. It's not obvious that for any > algorithm pfn_pdx_compression_setup() would leave compression disabled > when there are zero ranges. In principle, if it was written differently > for mask compression, there being no ranges could result in compression > simply squeezing out all of the address bits. Yet as long as we think > we're going to keep this in mind ...
It seemed to me that nr_rages == 0 (so no ranges reported) should result in no compression, for example on x86 this means there's no SRAT. > > Signed-off-by: Roger Pau Monné <roger....@cloud.com> > > Reviewed-by: Jan Beulich <jbeul...@suse.com> Thanks, Roger.
