Messages in this thread | | | Subject | Re: [PATCH] percpu/module resevation: change resevation size iff X86_VSMP is set | From | Eial Czerwacki <> | Date | Wed, 30 Jan 2019 12:33:32 +0200 |
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Greetings,
On 1/21/19 1:47 PM, Eial Czerwacki wrote: > as reported in bug #201339 (https://bugzilla.kernel.org/show_bug.cgi?id=201339) > by enabling X86_VSMP, INTERNODE_CACHE_BYTES's definition differs from the default one > causing the struct size to exceed the size ok 8KB. > > in order to avoid such issue, increse PERCPU_MODULE_RESERVE to 64KB if CONFIG_X86_VSMP is set. > > the value was caculated on linux 4.20.3, make allmodconfig all and the following oneliner: > for f in `find -name *.ko`; do echo $f; readelf -S $f |grep perc; done |grep data..percpu -B 1 |grep ko |while read r; do echo -n "$r: "; objdump --syms --section=.data..percpu $r|grep data |sort -n |awk '{c++; d=strtonum("0x" $1) + strtonum("0x" $5); if (m < d) m = d;} END {printf("%d vars-> last addr 0x%x ( %d )\n", c, m, m)}' ; done |column -t |sort -k 8 -n | awk '{print $8}'| paste -sd+ | bc > > Signed-off-by: Eial Czerwacki <eial@scalemp.com> > Signed-off-by: Shai Fultheim <shai@scalemp.com> > Signed-off-by: Oren Twaig <oren@scalemp.com> > --- > include/linux/percpu.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/include/linux/percpu.h b/include/linux/percpu.h > index 70b7123..6b79693 100644 > --- a/include/linux/percpu.h > +++ b/include/linux/percpu.h > @@ -14,7 +14,11 @@ > > /* enough to cover all DEFINE_PER_CPUs in modules */ > #ifdef CONFIG_MODULES > +#ifdef X86_VSMP > +#define PERCPU_MODULE_RESERVE (1 << 16) > +#else > #define PERCPU_MODULE_RESERVE (8 << 10) > +#endif > #else > #define PERCPU_MODULE_RESERVE 0 > #endif > is it possible to push this patch to mainline? it seems like no objections/comment regarding it exists. we'd like to fix the bug mentioned above.
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