"Aneesh Kumar K.V" <[email protected]> writes: > On 8/12/21 12:58 PM, Michael Ellerman wrote: >> Christophe Leroy <[email protected]> writes: >>> Le 10/08/2021 à 06:53, Aneesh Kumar K.V a écrit : >>>> Similar to x86/s390 add a debugfs file to tune >>>> tlb_single_page_flush_ceiling. >>>> >>>> Signed-off-by: Aneesh Kumar K.V <[email protected]> >>>> --- >>>> arch/powerpc/mm/book3s64/radix_tlb.c | 48 ++++++++++++++++++++++++++++ >>>> 1 file changed, 48 insertions(+) >>>> >>>> diff --git a/arch/powerpc/mm/book3s64/radix_tlb.c >>>> b/arch/powerpc/mm/book3s64/radix_tlb.c >>>> index aefc100d79a7..5cca0fe130e7 100644 >>>> --- a/arch/powerpc/mm/book3s64/radix_tlb.c >>>> +++ b/arch/powerpc/mm/book3s64/radix_tlb.c >>>> @@ -17,6 +17,7 @@ >> ... >>>> + >>>> +static int __init create_tlb_single_page_flush_ceiling(void) >>>> +{ >>>> + debugfs_create_file("tlb_single_page_flush_ceiling", S_IRUSR | S_IWUSR, >>>> + powerpc_debugfs_root, NULL, &fops_tlbflush); >>> >>> Could you just use debugfs_create_u32() instead of re-implementing simple >>> read and write ? >> >> Yeah AFAICS that should work fine. >> >> It could probably even be a u16? > > I was looking at switching all that to u64. Should i fallback to u16, > considering a tlb_signle_page_flush_ceiling value larger that 2**16 > doesn't make sense?
Hmm, if we make it u16 and someone writes a value >= 2^16 it just truncates the value to 0, which is a bit unfortunate. So maybe just make it u32, that way if someone writes a stupidly large value it stays large. cheers
