Messages in this thread | | | Date | Tue, 24 Oct 2023 13:30:04 -0700 | From | "H. Peter Anvin" <> | Subject | RE: [PATCH v2 1/6] x86/bugs: Add asm helpers for executing VERW |
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On October 24, 2023 12:40:02 PM PDT, "Luck, Tony" <tony.luck@intel.com> wrote: >> Sure it could, but it would mean the kernel is sitting on an average of 6 MB of unusable memory. It would also mean that unloaded modules would create holes in that memory which would have to be managed. > >On my Fedora38 desktop: > >$ lsmod | awk '{ bytes += $2 } END {print bytes/(1024*1024)}' >21.0859 > >Lots more than 6MB memory already essentially pinned by loaded modules. > >$ head -3 /proc/meminfo >MemTotal: 65507344 kB >MemFree: 56762336 kB >MemAvailable: 63358552 kB > >Pinning 20 or so Mbytes isn't going to make a dent in that free memory. > >Managing the holes for unloading/reloading modules adds some complexity ... but shouldn't be awful. > >If this code managed at finer granularity than "page", it would save some memory. > >$ lsmod | wc -l >123 > >All those modules rounding text/data up to 4K boundaries is wasting a bunch of it. > >-Tony > > >
Sure, but is it worth the effort?
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