Re: [PATCH] drm/amdgpu: Fix minmax error
Am 26.11.22 um 06:25 schrieb Luben Tuikov: Fix minmax compilation error by using the correct constant and correct integer suffix. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov Reviewed-by: Christian König --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..65715cb395d838 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -51,7 +51,7 @@ #include "amdgpu_amdkfd.h" #include "amdgpu_hmm.h" -#define MAX_WALK_BYTE (64ULL<<30) +#define MAX_WALK_BYTE (2UL << 30) /** * amdgpu_hmm_invalidate_gfx - callback to notify about mm change @@ -197,8 +197,8 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->start, hmm_range->end); /* Assuming 512MB takes maxmium 1 second to fault page address */ - timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL) * - HMM_RANGE_DEFAULT_TIMEOUT; + timeout = max((hmm_range->end - hmm_range->start) >> 29, 1UL); + timeout *= HMM_RANGE_DEFAULT_TIMEOUT; timeout = jiffies + msecs_to_jiffies(timeout); retry: base-commit: 9e95ce4c60631c1339204f8723008a715391f410
[PATCH] drm/amdgpu: Fix minmax error
Fix minmax compilation error by using the correct constant and correct integer suffix. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..65715cb395d838 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -51,7 +51,7 @@ #include "amdgpu_amdkfd.h" #include "amdgpu_hmm.h" -#define MAX_WALK_BYTE (64ULL<<30) +#define MAX_WALK_BYTE (2UL << 30) /** * amdgpu_hmm_invalidate_gfx - callback to notify about mm change @@ -197,8 +197,8 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->start, hmm_range->end); /* Assuming 512MB takes maxmium 1 second to fault page address */ - timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL) * - HMM_RANGE_DEFAULT_TIMEOUT; + timeout = max((hmm_range->end - hmm_range->start) >> 29, 1UL); + timeout *= HMM_RANGE_DEFAULT_TIMEOUT; timeout = jiffies + msecs_to_jiffies(timeout); retry: base-commit: 9e95ce4c60631c1339204f8723008a715391f410 -- 2.39.0.rc0
Re: [PATCH] drm/amdgpu: Fix minmax error
On 2022-11-25 16:03, James Zhu wrote: > > On 2022-11-25 14:42, Luben Tuikov wrote: >> On 2022-11-25 04:57, Christian König wrote: >>> >>> Am 25.11.22 um 09:33 schrieb Luben Tuikov: On 2022-11-25 02:59, Christian König wrote: > Am 25.11.22 um 08:56 schrieb Luben Tuikov: >> On 2022-11-25 02:45, Christian König wrote: >>> Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); >>> Since end is a local variable I would strongly prefer to just have it >>> use the correct type for it. >>> >>> Otherwise we might end up using something which doesn't work on all >>> architectures. >> They all appear to be "unsigned long". I thought, since we assign to >> hmm_range->end, we use that type. > Mhm, then why does the compiler complain here? Right... so MAX_WALK_BYTE is 2^36 ULL (diabolically defined as 64ULL<<30 :-) ), and this is why the minmax check complains. So, since the left-hand expression is unsigned long, i.e., hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); is, unsigned long = min(unsigned long long, unsigned long); The compiler complains. I'd really prefer MAX_WALK_BYTE be less than or equal to ULONG_MAX, >>> That's not only a preference, but a must have. Otherwise the code maybe >>> won't work as expected on 32bit architectures. >> Well, I don't know what to change MAX_WALK_BYTE to, and given the suggestion >> below to change to min_t(u64, ...), I wonder if messing with MAX_WALK_BYTE >> even matters--it wouldn't matter so long as the type in min_t() is u64. >> It's a macro at the moment. >> >> However, the LHS--struct hmm_range's members are all >> unsigned long and then we're essentially doing (unsigned long) = (u64), >> which on 32-bit is (u32) = (u64). > [JZ]MAX_WALK_BYTE can be reduce to #define MAX_WALK_BYTE (2UL<<30) Hi James--okay, I'll prep up a patch. Regards, Luben
Re: [PATCH] drm/amdgpu: Fix minmax error
On 2022-11-25 14:42, Luben Tuikov wrote: On 2022-11-25 04:57, Christian König wrote: Am 25.11.22 um 09:33 schrieb Luben Tuikov: On 2022-11-25 02:59, Christian König wrote: Am 25.11.22 um 08:56 schrieb Luben Tuikov: On 2022-11-25 02:45, Christian König wrote: Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); Since end is a local variable I would strongly prefer to just have it use the correct type for it. Otherwise we might end up using something which doesn't work on all architectures. They all appear to be "unsigned long". I thought, since we assign to hmm_range->end, we use that type. Mhm, then why does the compiler complain here? Right... so MAX_WALK_BYTE is 2^36 ULL (diabolically defined as 64ULL<<30 :-) ), and this is why the minmax check complains. So, since the left-hand expression is unsigned long, i.e., hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); is, unsigned long = min(unsigned long long, unsigned long); The compiler complains. I'd really prefer MAX_WALK_BYTE be less than or equal to ULONG_MAX, That's not only a preference, but a must have. Otherwise the code maybe won't work as expected on 32bit architectures. Well, I don't know what to change MAX_WALK_BYTE to, and given the suggestion below to change to min_t(u64, ...), I wonder if messing with MAX_WALK_BYTE even matters--it wouldn't matter so long as the type in min_t() is u64. It's a macro at the moment. However, the LHS--struct hmm_range's members are all unsigned long and then we're essentially doing (unsigned long) = (u64), which on 32-bit is (u32) = (u64). [JZ]MAX_WALK_BYTE can be reduce to #define MAX_WALK_BYTE (2UL<<30) Regards, Luben and be defined as UL. I mean, why is everything in struct hmm_range "unsigned long", but we set a high limit of 10__h for an end, and compare it to "end" to find the smaller? If our "end" could potentially be 10__h then shouldn't the members in struct hmm_range be unsigned long long as well? No, that the hmm range depends on the address space bits of the CPU is perfectly correct. Essentially this is just an userspace address range. Our problem here is that this code needs to work on both 32bit and 64bit systems. And on a 32bit system limiting the types wouldn't work correctly as far as I can see. So the compiler is complaining for rather good reasons and by using "min_t(UL" we just hide that instead of fixing the problem. I suggest to use "min_t(u64" instead. An intelligent compiler should even be capable of optimizing this away by looking at the input types on 32bit archs. And for the timeout, we have the (now) obvious, timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL); and I don't know why we necessarily need a "1ULL", when 1UL would do just fine, and then compilation passes for that statement. I can set this to 1UL, instead of using max_t(). I think just changing this to 1UL should be sufficient. Regards, Christian. Regards, Luben As far as I can see "unsigned long" is correct here, but if we somehow have a typecast then something is not working as expected. Is MAX_WALK_BYTE maybe of signed type? Would you prefer at the top of the function to define "timeout" and "end" as, typeof(hmm_range->end) end, timeout; Well for end that might make sense, but timeout is independent of the hmm range. Regards, Christian. Regards, Luben
Re: [PATCH] drm/amdgpu: Fix minmax error
On 2022-11-25 04:57, Christian König wrote: > > > Am 25.11.22 um 09:33 schrieb Luben Tuikov: >> On 2022-11-25 02:59, Christian König wrote: >>> Am 25.11.22 um 08:56 schrieb Luben Tuikov: On 2022-11-25 02:45, Christian König wrote: > Am 24.11.22 um 22:19 schrieb Luben Tuikov: >> Fix minmax compilation error by using min_t()/max_t(), of the assignment >> type. >> >> Cc: James Zhu >> Cc: Felix Kuehling >> Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large >> system memory") >> Signed-off-by: Luben Tuikov >> --- >> drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> index 8a2e5716d8dba2..d22d14b0ef0c84 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct >> mmu_interval_notifier *notifier, >> hmm_range->dev_private_owner = owner; >> >> do { >> -hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, >> end); >> +hmm_range->end = min_t(typeof(hmm_range->end), >> + hmm_range->start + MAX_WALK_BYTE, >> + end); > Since end is a local variable I would strongly prefer to just have it > use the correct type for it. > > Otherwise we might end up using something which doesn't work on all > architectures. They all appear to be "unsigned long". I thought, since we assign to hmm_range->end, we use that type. >>> Mhm, then why does the compiler complain here? >> Right... so MAX_WALK_BYTE is 2^36 ULL (diabolically defined as 64ULL<<30 :-) >> ), >> and this is why the minmax check complains. >> >> So, since the left-hand expression is unsigned long, >> i.e., >> hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); >> is, >> unsigned long = min(unsigned long long, unsigned long); >> The compiler complains. >> >> I'd really prefer MAX_WALK_BYTE be less than or equal to ULONG_MAX, > > That's not only a preference, but a must have. Otherwise the code maybe > won't work as expected on 32bit architectures. Well, I don't know what to change MAX_WALK_BYTE to, and given the suggestion below to change to min_t(u64, ...), I wonder if messing with MAX_WALK_BYTE even matters--it wouldn't matter so long as the type in min_t() is u64. It's a macro at the moment. However, the LHS--struct hmm_range's members are all unsigned long and then we're essentially doing (unsigned long) = (u64), which on 32-bit is (u32) = (u64). Regards, Luben > >> and be defined as UL. I mean, why is everything in struct hmm_range >> "unsigned long", but we set a high limit of 10__h for an end, and >> compare it to "end" to find the smaller? If our "end" could potentially >> be 10__h then shouldn't the members in struct hmm_range be >> unsigned long long as well? > > No, that the hmm range depends on the address space bits of the CPU is > perfectly correct. Essentially this is just an userspace address range. > > Our problem here is that this code needs to work on both 32bit and 64bit > systems. And on a 32bit system limiting the types wouldn't work > correctly as far as I can see. > > So the compiler is complaining for rather good reasons and by using > "min_t(UL" we just hide that instead of fixing the problem. > > I suggest to use "min_t(u64" instead. An intelligent compiler should > even be capable of optimizing this away by looking at the input types on > 32bit archs. > >> >> And for the timeout, we have the (now) obvious, >> >> timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL); >> >> and I don't know why we necessarily need a "1ULL", when 1UL would do just >> fine, >> and then compilation passes for that statement. I can set this to 1UL, >> instead >> of using max_t(). > > I think just changing this to 1UL should be sufficient. > > Regards, > Christian. > >> >> Regards, >> Luben >> >> >>> As far as I can see "unsigned long" is correct here, but if we somehow >>> have a typecast then something is not working as expected. >>> >>> Is MAX_WALK_BYTE maybe of signed type? >>> Would you prefer at the top of the function to define "timeout" and "end" as, typeof(hmm_range->end) end, timeout; >>> Well for end that might make sense, but timeout is independent of the >>> hmm range. >>> >>> Regards, >>> Christian. >>> Regards, Luben >
Re: [PATCH] drm/amdgpu: Fix minmax error
Am 25.11.22 um 09:33 schrieb Luben Tuikov: On 2022-11-25 02:59, Christian König wrote: Am 25.11.22 um 08:56 schrieb Luben Tuikov: On 2022-11-25 02:45, Christian König wrote: Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); Since end is a local variable I would strongly prefer to just have it use the correct type for it. Otherwise we might end up using something which doesn't work on all architectures. They all appear to be "unsigned long". I thought, since we assign to hmm_range->end, we use that type. Mhm, then why does the compiler complain here? Right... so MAX_WALK_BYTE is 2^36 ULL (diabolically defined as 64ULL<<30 :-) ), and this is why the minmax check complains. So, since the left-hand expression is unsigned long, i.e., hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); is, unsigned long = min(unsigned long long, unsigned long); The compiler complains. I'd really prefer MAX_WALK_BYTE be less than or equal to ULONG_MAX, That's not only a preference, but a must have. Otherwise the code maybe won't work as expected on 32bit architectures. and be defined as UL. I mean, why is everything in struct hmm_range "unsigned long", but we set a high limit of 10__h for an end, and compare it to "end" to find the smaller? If our "end" could potentially be 10__h then shouldn't the members in struct hmm_range be unsigned long long as well? No, that the hmm range depends on the address space bits of the CPU is perfectly correct. Essentially this is just an userspace address range. Our problem here is that this code needs to work on both 32bit and 64bit systems. And on a 32bit system limiting the types wouldn't work correctly as far as I can see. So the compiler is complaining for rather good reasons and by using "min_t(UL" we just hide that instead of fixing the problem. I suggest to use "min_t(u64" instead. An intelligent compiler should even be capable of optimizing this away by looking at the input types on 32bit archs. And for the timeout, we have the (now) obvious, timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL); and I don't know why we necessarily need a "1ULL", when 1UL would do just fine, and then compilation passes for that statement. I can set this to 1UL, instead of using max_t(). I think just changing this to 1UL should be sufficient. Regards, Christian. Regards, Luben As far as I can see "unsigned long" is correct here, but if we somehow have a typecast then something is not working as expected. Is MAX_WALK_BYTE maybe of signed type? Would you prefer at the top of the function to define "timeout" and "end" as, typeof(hmm_range->end) end, timeout; Well for end that might make sense, but timeout is independent of the hmm range. Regards, Christian. Regards, Luben
Re: [PATCH] drm/amdgpu: Fix minmax error
On 2022-11-25 02:59, Christian König wrote: > Am 25.11.22 um 08:56 schrieb Luben Tuikov: >> On 2022-11-25 02:45, Christian König wrote: >>> >>> Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); >>> Since end is a local variable I would strongly prefer to just have it >>> use the correct type for it. >>> >>> Otherwise we might end up using something which doesn't work on all >>> architectures. >> They all appear to be "unsigned long". I thought, since we assign to >> hmm_range->end, we use that type. > > Mhm, then why does the compiler complain here? Right... so MAX_WALK_BYTE is 2^36 ULL (diabolically defined as 64ULL<<30 :-) ), and this is why the minmax check complains. So, since the left-hand expression is unsigned long, i.e., hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); is, unsigned long = min(unsigned long long, unsigned long); The compiler complains. I'd really prefer MAX_WALK_BYTE be less than or equal to ULONG_MAX, and be defined as UL. I mean, why is everything in struct hmm_range "unsigned long", but we set a high limit of 10__h for an end, and compare it to "end" to find the smaller? If our "end" could potentially be 10__h then shouldn't the members in struct hmm_range be unsigned long long as well? And for the timeout, we have the (now) obvious, timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL); and I don't know why we necessarily need a "1ULL", when 1UL would do just fine, and then compilation passes for that statement. I can set this to 1UL, instead of using max_t(). Regards, Luben > > As far as I can see "unsigned long" is correct here, but if we somehow > have a typecast then something is not working as expected. > > Is MAX_WALK_BYTE maybe of signed type? > >> >> Would you prefer at the top of the function to define "timeout" and "end" as, >> typeof(hmm_range->end) end, timeout; > > Well for end that might make sense, but timeout is independent of the > hmm range. > > Regards, > Christian. > >> >> Regards, >> Luben >> >
Re: [PATCH] drm/amdgpu: Fix minmax error
Am 25.11.22 um 08:56 schrieb Luben Tuikov: On 2022-11-25 02:45, Christian König wrote: Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); Since end is a local variable I would strongly prefer to just have it use the correct type for it. Otherwise we might end up using something which doesn't work on all architectures. They all appear to be "unsigned long". I thought, since we assign to hmm_range->end, we use that type. Mhm, then why does the compiler complain here? As far as I can see "unsigned long" is correct here, but if we somehow have a typecast then something is not working as expected. Is MAX_WALK_BYTE maybe of signed type? Would you prefer at the top of the function to define "timeout" and "end" as, typeof(hmm_range->end) end, timeout; Well for end that might make sense, but timeout is independent of the hmm range. Regards, Christian. Regards, Luben
Re: [PATCH] drm/amdgpu: Fix minmax error
On 2022-11-25 02:45, Christian König wrote: > > > Am 24.11.22 um 22:19 schrieb Luben Tuikov: >> Fix minmax compilation error by using min_t()/max_t(), of the assignment >> type. >> >> Cc: James Zhu >> Cc: Felix Kuehling >> Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large >> system memory") >> Signed-off-by: Luben Tuikov >> --- >> drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- >> 1 file changed, 7 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> index 8a2e5716d8dba2..d22d14b0ef0c84 100644 >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c >> @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct >> mmu_interval_notifier *notifier, >> hmm_range->dev_private_owner = owner; >> >> do { >> -hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); >> +hmm_range->end = min_t(typeof(hmm_range->end), >> + hmm_range->start + MAX_WALK_BYTE, >> + end); > > Since end is a local variable I would strongly prefer to just have it > use the correct type for it. > > Otherwise we might end up using something which doesn't work on all > architectures. They all appear to be "unsigned long". I thought, since we assign to hmm_range->end, we use that type. Would you prefer at the top of the function to define "timeout" and "end" as, typeof(hmm_range->end) end, timeout; Regards, Luben
Re: [PATCH] drm/amdgpu: Fix minmax error
Am 24.11.22 um 22:19 schrieb Luben Tuikov: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); Since end is a local variable I would strongly prefer to just have it use the correct type for it. Otherwise we might end up using something which doesn't work on all architectures. Regards, Christian. pr_debug("hmm range: start = 0x%lx, end = 0x%lx", hmm_range->start, hmm_range->end); /* Assuming 512MB takes maxmium 1 second to fault page address */ - timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL) * - HMM_RANGE_DEFAULT_TIMEOUT; + timeout = max_t(typeof(timeout), + (hmm_range->end - hmm_range->start) >> 29, + 1ULL); + timeout *= HMM_RANGE_DEFAULT_TIMEOUT; timeout = jiffies + msecs_to_jiffies(timeout); retry: base-commit: d5e8f4912061ad2e577b4909556e1364e2c2018e prerequisite-patch-id: 6024d0c36cae3e4a995a8fcf787b91f511a37486
Re: [PATCH] drm/amdgpu: Fix minmax error
ThispatchisReviewed-by:JamesZhu On 2022-11-24 16:19, Luben Tuikov wrote: Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); pr_debug("hmm range: start = 0x%lx, end = 0x%lx", hmm_range->start, hmm_range->end); /* Assuming 512MB takes maxmium 1 second to fault page address */ - timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL) * - HMM_RANGE_DEFAULT_TIMEOUT; + timeout = max_t(typeof(timeout), + (hmm_range->end - hmm_range->start) >> 29, + 1ULL); + timeout *= HMM_RANGE_DEFAULT_TIMEOUT; timeout = jiffies + msecs_to_jiffies(timeout); retry: base-commit: d5e8f4912061ad2e577b4909556e1364e2c2018e prerequisite-patch-id: 6024d0c36cae3e4a995a8fcf787b91f511a37486
[PATCH] drm/amdgpu: Fix minmax error
Fix minmax compilation error by using min_t()/max_t(), of the assignment type. Cc: James Zhu Cc: Felix Kuehling Fixes: 58170a7a002ad6 ("drm/amdgpu: fix stall on CPU when allocate large system memory") Signed-off-by: Luben Tuikov --- drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c | 10 +++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c index 8a2e5716d8dba2..d22d14b0ef0c84 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_hmm.c @@ -191,14 +191,18 @@ int amdgpu_hmm_range_get_pages(struct mmu_interval_notifier *notifier, hmm_range->dev_private_owner = owner; do { - hmm_range->end = min(hmm_range->start + MAX_WALK_BYTE, end); + hmm_range->end = min_t(typeof(hmm_range->end), + hmm_range->start + MAX_WALK_BYTE, + end); pr_debug("hmm range: start = 0x%lx, end = 0x%lx", hmm_range->start, hmm_range->end); /* Assuming 512MB takes maxmium 1 second to fault page address */ - timeout = max((hmm_range->end - hmm_range->start) >> 29, 1ULL) * - HMM_RANGE_DEFAULT_TIMEOUT; + timeout = max_t(typeof(timeout), + (hmm_range->end - hmm_range->start) >> 29, + 1ULL); + timeout *= HMM_RANGE_DEFAULT_TIMEOUT; timeout = jiffies + msecs_to_jiffies(timeout); retry: base-commit: d5e8f4912061ad2e577b4909556e1364e2c2018e prerequisite-patch-id: 6024d0c36cae3e4a995a8fcf787b91f511a37486 -- 2.39.0.rc0