Re: [Qemu-devel] [PATCH v4 29/49] tests/tcg/arm: disable -p 32768 mmap test
On 05/17/2018 06:34 PM, Richard Henderson wrote: > On 05/17/2018 02:24 PM, Alex Bennée wrote: >> >> Richard Henderson writes: >> >>> On 05/17/2018 10:46 AM, Alex Bennée wrote: Broken since I updated to 18.04 Signed-off-by: Alex Bennée --- tests/tcg/arm/Makefile.target | 8 1 file changed, 8 insertions(+) >>> >>> Meh. Most of these fail for hosts with 64k pages. >>> So, sure, disable this one, but I don't think that >>> the others are useful either. >> >> I'm not entirely sure what the point of -p is meant to be. Is it just a >> performance hack for linux-user to have bigger pages? We are not using >> softmmu but I guess it affects the PageDesc structures? > > I think it was just meant for testing, but I really have no idea. > > If we actually had better support for mismatched host/guest page sizes, then > one could view -p as a way to choose between legitimate guest page sizes. > E.g. > 8k, 16k, 64k are all legitimate for aarch64. 8k + 16k on aarch64: Tested-by: Philippe Mathieu-Daudé
Re: [Qemu-devel] [PATCH v4 29/49] tests/tcg/arm: disable -p 32768 mmap test
On 05/17/2018 02:24 PM, Alex Bennée wrote: > > Richard Henderson writes: > >> On 05/17/2018 10:46 AM, Alex Bennée wrote: >>> Broken since I updated to 18.04 >>> >>> Signed-off-by: Alex Bennée >>> --- >>> tests/tcg/arm/Makefile.target | 8 >>> 1 file changed, 8 insertions(+) >> >> Meh. Most of these fail for hosts with 64k pages. >> So, sure, disable this one, but I don't think that >> the others are useful either. > > I'm not entirely sure what the point of -p is meant to be. Is it just a > performance hack for linux-user to have bigger pages? We are not using > softmmu but I guess it affects the PageDesc structures? I think it was just meant for testing, but I really have no idea. If we actually had better support for mismatched host/guest page sizes, then one could view -p as a way to choose between legitimate guest page sizes. E.g. 8k, 16k, 64k are all legitimate for aarch64. r~
Re: [Qemu-devel] [PATCH v4 29/49] tests/tcg/arm: disable -p 32768 mmap test
Richard Henderson writes: > On 05/17/2018 10:46 AM, Alex Bennée wrote: >> Broken since I updated to 18.04 >> >> Signed-off-by: Alex Bennée >> --- >> tests/tcg/arm/Makefile.target | 8 >> 1 file changed, 8 insertions(+) > > Meh. Most of these fail for hosts with 64k pages. > So, sure, disable this one, but I don't think that > the others are useful either. I'm not entirely sure what the point of -p is meant to be. Is it just a performance hack for linux-user to have bigger pages? We are not using softmmu but I guess it affects the PageDesc structures? -- Alex Bennée
Re: [Qemu-devel] [PATCH v4 29/49] tests/tcg/arm: disable -p 32768 mmap test
On 05/17/2018 10:46 AM, Alex Bennée wrote: > Broken since I updated to 18.04 > > Signed-off-by: Alex Bennée > --- > tests/tcg/arm/Makefile.target | 8 > 1 file changed, 8 insertions(+) Meh. Most of these fail for hosts with 64k pages. So, sure, disable this one, but I don't think that the others are useful either. r~
