Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
Wei Yang wrote: > Use ROUND_UP() to define, which is a little bit easy to read. > > Signed-off-by: Wei Yang Reviewed-by: Juan Quintela
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On Sun, Oct 13, 2019 at 07:38:04PM -0700, Richard Henderson wrote: >On 10/13/19 6:01 PM, Wei Yang wrote: >>> No, please. >>> >>> (1) The compiler does not know that qemu_*host_page_size is a power of 2, >>> and >>> will generate a real division at runtime. The same is true for >>> TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY. >>> >> >> Confused >> >> The definition of ROUND_UP is: >> >> #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d))) > >Ah, my bad, I did confuse this with QEMU_ALIGN_UP. > >Hmm. > > lea -1(n, size), t > neg size > and size, t > >vs > > mov mask, t > not t > add n, t > and mask, t > >which is what I proposed here > >>> https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html > >I'm ok with your version. > >Reviewed-by: Richard Henderson > Thanks for your clarification. Have a nice day > >r~ > -- Wei Yang Help you, Help me
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On 10/13/19 6:01 PM, Wei Yang wrote: >> No, please. >> >> (1) The compiler does not know that qemu_*host_page_size is a power of 2, and >> will generate a real division at runtime. The same is true for >> TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY. >> > > Confused > > The definition of ROUND_UP is: > > #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d))) Ah, my bad, I did confuse this with QEMU_ALIGN_UP. Hmm. lea -1(n, size), t neg size and size, t vs mov mask, t not t add n, t and mask, t which is what I proposed here >> https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html I'm ok with your version. Reviewed-by: Richard Henderson r~
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On Sun, Oct 13, 2019 at 11:56:35AM -0400, Richard Henderson wrote: >On 10/12/19 10:11 PM, Wei Yang wrote: >> Use ROUND_UP() to define, which is a little bit easy to read. >> >> Signed-off-by: Wei Yang >> --- >> include/exec/cpu-all.h | 7 +++ >> 1 file changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h >> index ad9ab85eb3..255bb186ac 100644 >> --- a/include/exec/cpu-all.h >> +++ b/include/exec/cpu-all.h >> @@ -220,7 +220,7 @@ extern int target_page_bits; >> >> #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) >> #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) >> -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & >> TARGET_PAGE_MASK) >> +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) >> >> /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even >> * when intptr_t is 32-bit and we are aligning a long long. >> @@ -228,9 +228,8 @@ extern int target_page_bits; >> extern uintptr_t qemu_host_page_size; >> extern intptr_t qemu_host_page_mask; >> >> -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & >> qemu_host_page_mask) >> -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) >> & \ >> -qemu_real_host_page_mask) >> +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size) >> +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), >> qemu_real_host_page_size) > > >No, please. > >(1) The compiler does not know that qemu_*host_page_size is a power of 2, and >will generate a real division at runtime. The same is true for >TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY. > Confused The definition of ROUND_UP is: #define ROUND_UP(n, d) (((n) + (d) - 1) & -(0 ? (n) : (d))) Why it will do division? This will be expanded to the same form as the original code, if my understanding is correct. Would you mind telling me more? >(2) The first hunk conflicts with an in-flight patch of mine: > >https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html > > >r~ -- Wei Yang Help you, Help me
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On Sun, Oct 13, 2019 at 11:56:35AM -0400, Richard Henderson wrote: > On 10/12/19 10:11 PM, Wei Yang wrote: > > Use ROUND_UP() to define, which is a little bit easy to read. > > > > Signed-off-by: Wei Yang > > --- > > include/exec/cpu-all.h | 7 +++ > > 1 file changed, 3 insertions(+), 4 deletions(-) > > > > diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h > > index ad9ab85eb3..255bb186ac 100644 > > --- a/include/exec/cpu-all.h > > +++ b/include/exec/cpu-all.h > > @@ -220,7 +220,7 @@ extern int target_page_bits; > > > > #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) > > #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) > > -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & > > TARGET_PAGE_MASK) > > +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) > > > > /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even > > * when intptr_t is 32-bit and we are aligning a long long. > > @@ -228,9 +228,8 @@ extern int target_page_bits; > > extern uintptr_t qemu_host_page_size; > > extern intptr_t qemu_host_page_mask; > > > > -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & > > qemu_host_page_mask) > > -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - > > 1) & \ > > -qemu_real_host_page_mask) > > +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size) > > +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), > > qemu_real_host_page_size) > > > No, please. > > (1) The compiler does not know that qemu_*host_page_size is a power of 2, and > will generate a real division at runtime. The same is true for > TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY. Ouch, good point, I didn't think of that when I gave an R-b. > (2) The first hunk conflicts with an in-flight patch of mine: > > https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html > > > r~ > -- David Gibson| I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson signature.asc Description: PGP signature
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On 10/12/19 10:11 PM, Wei Yang wrote: > Use ROUND_UP() to define, which is a little bit easy to read. > > Signed-off-by: Wei Yang > --- > include/exec/cpu-all.h | 7 +++ > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h > index ad9ab85eb3..255bb186ac 100644 > --- a/include/exec/cpu-all.h > +++ b/include/exec/cpu-all.h > @@ -220,7 +220,7 @@ extern int target_page_bits; > > #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) > #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) > -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & > TARGET_PAGE_MASK) > +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) > > /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even > * when intptr_t is 32-bit and we are aligning a long long. > @@ -228,9 +228,8 @@ extern int target_page_bits; > extern uintptr_t qemu_host_page_size; > extern intptr_t qemu_host_page_mask; > > -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & > qemu_host_page_mask) > -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) > & \ > -qemu_real_host_page_mask) > +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size) > +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_real_host_page_size) No, please. (1) The compiler does not know that qemu_*host_page_size is a power of 2, and will generate a real division at runtime. The same is true for TARGET_PAGE_SIZE when TARGET_PAGE_BITS_VARY. (2) The first hunk conflicts with an in-flight patch of mine: https://lists.gnu.org/archive/html/qemu-devel/2019-09/msg04526.html r~
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On Sun, Oct 13, 2019 at 10:11:44AM +0800, Wei Yang wrote: > Use ROUND_UP() to define, which is a little bit easy to read. > > Signed-off-by: Wei Yang Reviewed-by: David Gibson > --- > include/exec/cpu-all.h | 7 +++ > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h > index ad9ab85eb3..255bb186ac 100644 > --- a/include/exec/cpu-all.h > +++ b/include/exec/cpu-all.h > @@ -220,7 +220,7 @@ extern int target_page_bits; > > #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) > #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) > -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & > TARGET_PAGE_MASK) > +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) > > /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even > * when intptr_t is 32-bit and we are aligning a long long. > @@ -228,9 +228,8 @@ extern int target_page_bits; > extern uintptr_t qemu_host_page_size; > extern intptr_t qemu_host_page_mask; > > -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & > qemu_host_page_mask) > -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) > & \ > -qemu_real_host_page_mask) > +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size) > +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_real_host_page_size) > > /* same as PROT_xxx */ > #define PAGE_READ 0x0001 -- David Gibson| I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson signature.asc Description: PGP signature
Re: [PATCH 1/2] cpu: use ROUND_UP() to define xxx_PAGE_ALIGN
On Sun, Oct 13, 2019 at 10:11:44AM +0800, Wei Yang wrote: > Use ROUND_UP() to define, which is a little bit easy to read. > > Signed-off-by: Wei Yang Reviewed-by: Michael S. Tsirkin > --- > include/exec/cpu-all.h | 7 +++ > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h > index ad9ab85eb3..255bb186ac 100644 > --- a/include/exec/cpu-all.h > +++ b/include/exec/cpu-all.h > @@ -220,7 +220,7 @@ extern int target_page_bits; > > #define TARGET_PAGE_SIZE (1 << TARGET_PAGE_BITS) > #define TARGET_PAGE_MASK ~(TARGET_PAGE_SIZE - 1) > -#define TARGET_PAGE_ALIGN(addr) (((addr) + TARGET_PAGE_SIZE - 1) & > TARGET_PAGE_MASK) > +#define TARGET_PAGE_ALIGN(addr) ROUND_UP((addr), TARGET_PAGE_SIZE) > > /* Using intptr_t ensures that qemu_*_page_mask is sign-extended even > * when intptr_t is 32-bit and we are aligning a long long. > @@ -228,9 +228,8 @@ extern int target_page_bits; > extern uintptr_t qemu_host_page_size; > extern intptr_t qemu_host_page_mask; > > -#define HOST_PAGE_ALIGN(addr) (((addr) + qemu_host_page_size - 1) & > qemu_host_page_mask) > -#define REAL_HOST_PAGE_ALIGN(addr) (((addr) + qemu_real_host_page_size - 1) > & \ > -qemu_real_host_page_mask) > +#define HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_host_page_size) > +#define REAL_HOST_PAGE_ALIGN(addr) ROUND_UP((addr), qemu_real_host_page_size) > > /* same as PROT_xxx */ > #define PAGE_READ 0x0001 > -- > 2.17.1
