[PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Bruce Richardson]

The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
assumed that each pointer was always 8B in size.

Bruce Richardson (4):
  net/i40e: fix AVX-512 pointer copy on 32-bit
  net/ice: fix AVX-512 pointer copy on 32-bit
  net/iavf: fix AVX-512 pointer copy on 32-bit
  common/idpf: fix AVX-512 pointer copy on 32-bit

 drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
 drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
 drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
 drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
 4 files changed, 28 insertions(+)

--
2.43.0

[PATCH 1/4] net/i40e: fix AVX-512 pointer copy on 32-bit

[Bruce Richardson]

The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
copying 32 pointers only requires half the number of AVX-512 load store
operations.

Fixes: 5171b4ee6b6b ("net/i40e: optimize Tx by using AVX512")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/net/i40e/i40e_rxtx_vec_avx512.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx512.c b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
index 0238b03f8a..3b2750221b 100644
--- a/drivers/net/i40e/i40e_rxtx_vec_avx512.c
+++ b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
@@ -799,6 +799,7 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
 		uint32_t copied = 0;
 		/* n is multiple of 32 */
 		while (copied < n) {
+#ifdef RTE_ARCH_64
 			const __m512i a = _mm512_load_si512(&txep[copied]);
 			const __m512i b = _mm512_load_si512(&txep[copied + 8]);
 			const __m512i c = _mm512_load_si512(&txep[copied + 16]);
@@ -808,6 +809,12 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
 			_mm512_storeu_si512(&cache_objs[copied + 8], b);
 			_mm512_storeu_si512(&cache_objs[copied + 16], c);
 			_mm512_storeu_si512(&cache_objs[copied + 24], d);
+#else
+			const __m512i a = _mm512_load_si512(&txep[copied]);
+			const __m512i b = _mm512_load_si512(&txep[copied + 16]);
+			_mm512_storeu_si512(&cache_objs[copied], a);
+			_mm512_storeu_si512(&cache_objs[copied + 16], b);
+#endif
 			copied += 32;
 		}
 		cache->len += n;
-- 
2.43.0

RE: [PATCH 1/4] net/i40e: fix AVX-512 pointer copy on 32-bit

[Stokes, Ian]

> The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
> copying 32 pointers only requires half the number of AVX-512 load store
> operations.
> 
> Fixes: 5171b4ee6b6b ("net/i40e: optimize Tx by using AVX512")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>  drivers/net/i40e/i40e_rxtx_vec_avx512.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/i40e/i40e_rxtx_vec_avx512.c
> b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
> index 0238b03f8a..3b2750221b 100644
> --- a/drivers/net/i40e/i40e_rxtx_vec_avx512.c
> +++ b/drivers/net/i40e/i40e_rxtx_vec_avx512.c
> @@ -799,6 +799,7 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
>  		uint32_t copied = 0;
>  		/* n is multiple of 32 */
>  		while (copied < n) {
> +#ifdef RTE_ARCH_64
>  			const __m512i a = _mm512_load_si512(&txep[copied]);
>  			const __m512i b = _mm512_load_si512(&txep[copied +
> 8]);
>  			const __m512i c = _mm512_load_si512(&txep[copied +
> 16]);
> @@ -808,6 +809,12 @@ i40e_tx_free_bufs_avx512(struct i40e_tx_queue *txq)
>  			_mm512_storeu_si512(&cache_objs[copied + 8], b);
>  			_mm512_storeu_si512(&cache_objs[copied + 16], c);
>  			_mm512_storeu_si512(&cache_objs[copied + 24], d);
> +#else
> +			const __m512i a = _mm512_load_si512(&txep[copied]);
> +			const __m512i b = _mm512_load_si512(&txep[copied +
> 16]);
> +			_mm512_storeu_si512(&cache_objs[copied], a);
> +			_mm512_storeu_si512(&cache_objs[copied + 16], b);
> +#endif
>  			copied += 32;
>  		}
>  		cache->len += n;
> --
> 2.43.0

Looks good to me, ACKED.

Thanks
Ian

[PATCH 2/4] net/ice: fix AVX-512 pointer copy on 32-bit

[Bruce Richardson]

The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
copying 32 pointers only requires half the number of AVX-512 load store
operations.

Fixes: a4e480de268e ("net/ice: optimize Tx by using AVX512")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/net/ice/ice_rxtx_vec_avx512.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ice/ice_rxtx_vec_avx512.c b/drivers/net/ice/ice_rxtx_vec_avx512.c
index 04148e8ea2..add095ef06 100644
--- a/drivers/net/ice/ice_rxtx_vec_avx512.c
+++ b/drivers/net/ice/ice_rxtx_vec_avx512.c
@@ -907,6 +907,7 @@ ice_tx_free_bufs_avx512(struct ice_tx_queue *txq)
 		uint32_t copied = 0;
 		/* n is multiple of 32 */
 		while (copied < n) {
+#ifdef RTE_ARCH_64
 			const __m512i a = _mm512_loadu_si512(&txep[copied]);
 			const __m512i b = _mm512_loadu_si512(&txep[copied + 8]);
 			const __m512i c = _mm512_loadu_si512(&txep[copied + 16]);
@@ -916,6 +917,12 @@ ice_tx_free_bufs_avx512(struct ice_tx_queue *txq)
 			_mm512_storeu_si512(&cache_objs[copied + 8], b);
 			_mm512_storeu_si512(&cache_objs[copied + 16], c);
 			_mm512_storeu_si512(&cache_objs[copied + 24], d);
+#else
+			const __m512i a = _mm512_loadu_si512(&txep[copied]);
+			const __m512i b = _mm512_loadu_si512(&txep[copied + 16]);
+			_mm512_storeu_si512(&cache_objs[copied], a);
+			_mm512_storeu_si512(&cache_objs[copied + 16], b);
+#endif
 			copied += 32;
 		}
 		cache->len += n;
-- 
2.43.0

RE: [PATCH 2/4] net/ice: fix AVX-512 pointer copy on 32-bit

[Stokes, Ian]

> The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
> copying 32 pointers only requires half the number of AVX-512 load store
> operations.
> 
> Fixes: a4e480de268e ("net/ice: optimize Tx by using AVX512")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
>  drivers/net/ice/ice_rxtx_vec_avx512.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/net/ice/ice_rxtx_vec_avx512.c
> b/drivers/net/ice/ice_rxtx_vec_avx512.c
> index 04148e8ea2..add095ef06 100644
> --- a/drivers/net/ice/ice_rxtx_vec_avx512.c
> +++ b/drivers/net/ice/ice_rxtx_vec_avx512.c
> @@ -907,6 +907,7 @@ ice_tx_free_bufs_avx512(struct ice_tx_queue *txq)
>  		uint32_t copied = 0;
>  		/* n is multiple of 32 */
>  		while (copied < n) {
> +#ifdef RTE_ARCH_64
>  			const __m512i a =
> _mm512_loadu_si512(&txep[copied]);
>  			const __m512i b = _mm512_loadu_si512(&txep[copied
> + 8]);
>  			const __m512i c = _mm512_loadu_si512(&txep[copied +
> 16]);
> @@ -916,6 +917,12 @@ ice_tx_free_bufs_avx512(struct ice_tx_queue *txq)
>  			_mm512_storeu_si512(&cache_objs[copied + 8], b);
>  			_mm512_storeu_si512(&cache_objs[copied + 16], c);
>  			_mm512_storeu_si512(&cache_objs[copied + 24], d);
> +#else
> +			const __m512i a =
> _mm512_loadu_si512(&txep[copied]);
> +			const __m512i b = _mm512_loadu_si512(&txep[copied
> + 16]);
> +			_mm512_storeu_si512(&cache_objs[copied], a);
> +			_mm512_storeu_si512(&cache_objs[copied + 16], b);
> +#endif
>  			copied += 32;
>  		}
>  		cache->len += n;
> --
 LGTM, Acked.

Thanks
Ian

[PATCH 3/4] net/iavf: fix AVX-512 pointer copy on 32-bit

[Bruce Richardson]

The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
copying 32 pointers only requires half the number of AVX-512 load store
operations.

Fixes: 9ab9514c150e ("net/iavf: enable AVX512 for Tx")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/net/iavf/iavf_rxtx_vec_avx512.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/iavf/iavf_rxtx_vec_avx512.c b/drivers/net/iavf/iavf_rxtx_vec_avx512.c
index 3bb6f305df..d6a861bf80 100644
--- a/drivers/net/iavf/iavf_rxtx_vec_avx512.c
+++ b/drivers/net/iavf/iavf_rxtx_vec_avx512.c
@@ -1892,6 +1892,7 @@ iavf_tx_free_bufs_avx512(struct iavf_tx_queue *txq)
 		uint32_t copied = 0;
 		/* n is multiple of 32 */
 		while (copied < n) {
+#ifdef RTE_ARCH_64
 			const __m512i a = _mm512_loadu_si512(&txep[copied]);
 			const __m512i b = _mm512_loadu_si512(&txep[copied + 8]);
 			const __m512i c = _mm512_loadu_si512(&txep[copied + 16]);
@@ -1901,6 +1902,12 @@ iavf_tx_free_bufs_avx512(struct iavf_tx_queue *txq)
 			_mm512_storeu_si512(&cache_objs[copied + 8], b);
 			_mm512_storeu_si512(&cache_objs[copied + 16], c);
 			_mm512_storeu_si512(&cache_objs[copied + 24], d);
+#else
+			const __m512i a = _mm512_loadu_si512(&txep[copied]);
+			const __m512i b = _mm512_loadu_si512(&txep[copied + 16]);
+			_mm512_storeu_si512(&cache_objs[copied], a);
+			_mm512_storeu_si512(&cache_objs[copied + 16], b);
+#endif
 			copied += 32;
 		}
 		cache->len += n;
-- 
2.43.0

[PATCH 4/4] common/idpf: fix AVX-512 pointer copy on 32-bit

[Bruce Richardson]

The size of a pointer on 32-bit is only 4 rather than 8 bytes, so
copying 32 pointers only requires half the number of AVX-512 load store
operations.

Fixes: 5bf87b45b2c8 ("net/idpf: add AVX512 data path for single queue model")
Cc: stable@dpdk.org

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/common/idpf/idpf_common_rxtx_avx512.c b/drivers/common/idpf/idpf_common_rxtx_avx512.c
index 3b5e124ec8..b8450b03ae 100644
--- a/drivers/common/idpf/idpf_common_rxtx_avx512.c
+++ b/drivers/common/idpf/idpf_common_rxtx_avx512.c
@@ -1043,6 +1043,7 @@ idpf_tx_singleq_free_bufs_avx512(struct idpf_tx_queue *txq)
 		uint32_t copied = 0;
 		/* n is multiple of 32 */
 		while (copied < n) {
+#ifdef RTE_ARCH_64
 			const __m512i a = _mm512_loadu_si512(&txep[copied]);
 			const __m512i b = _mm512_loadu_si512(&txep[copied + 8]);
 			const __m512i c = _mm512_loadu_si512(&txep[copied + 16]);
@@ -1052,6 +1053,12 @@ idpf_tx_singleq_free_bufs_avx512(struct idpf_tx_queue *txq)
 			_mm512_storeu_si512(&cache_objs[copied + 8], b);
 			_mm512_storeu_si512(&cache_objs[copied + 16], c);
 			_mm512_storeu_si512(&cache_objs[copied + 24], d);
+#else
+			const __m512i a = _mm512_loadu_si512(&txep[copied]);
+			const __m512i b = _mm512_loadu_si512(&txep[copied + 16]);
+			_mm512_storeu_si512(&cache_objs[copied], a);
+			_mm512_storeu_si512(&cache_objs[copied + 16], b);
+#endif
 			copied += 32;
 		}
 		cache->len += n;
-- 
2.43.0

RE: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Stokes, Ian]

> The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> assumed that each pointer was always 8B in size.
> 
> Bruce Richardson (4):
>   net/i40e: fix AVX-512 pointer copy on 32-bit
>   net/ice: fix AVX-512 pointer copy on 32-bit
>   net/iavf: fix AVX-512 pointer copy on 32-bit
>   common/idpf: fix AVX-512 pointer copy on 32-bit
> 
>  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
>  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
>  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
>  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++

Series looks good to me.

Series-acked-by: Ian Stokes <ian.stokes@intel.com>

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Bruce Richardson]

On Mon, Sep 30, 2024 at 02:31:56PM +0100, Stokes, Ian wrote:
> > The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> > assumed that each pointer was always 8B in size.
> > 
> > Bruce Richardson (4):
> >   net/i40e: fix AVX-512 pointer copy on 32-bit
> >   net/ice: fix AVX-512 pointer copy on 32-bit
> >   net/iavf: fix AVX-512 pointer copy on 32-bit
> >   common/idpf: fix AVX-512 pointer copy on 32-bit
> > 
> >  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
> >  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
> >  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
> >  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
> 
> Series looks good to me.
> 
> Series-acked-by: Ian Stokes <ian.stokes@intel.com>
> 
Applied to dpdk-next-net-intel.

/Bruce

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[David Marchand]

On Fri, Sep 6, 2024 at 4:11 PM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> assumed that each pointer was always 8B in size.
>
> Bruce Richardson (4):
>   net/i40e: fix AVX-512 pointer copy on 32-bit
>   net/ice: fix AVX-512 pointer copy on 32-bit
>   net/iavf: fix AVX-512 pointer copy on 32-bit
>   common/idpf: fix AVX-512 pointer copy on 32-bit
>
>  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
>  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
>  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
>  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
>  4 files changed, 28 insertions(+)

Sorry, not directly related to this series, but as I was checking some
AVX512 patch, I suspect some drivers are missing runtime checks for
availability of some AVX512 instructions:

$ for meson in $(git grep -l __AVX512[^_]*__
'drivers/**/meson.build'); do dir=$(dirname $meson); for flag in $(git
grep -ho __AVX512[^_]*__ $dir | sort -u); do flag=${flag%%__};
flag=${flag##__}; git grep -ql
rte_cpu_get_flag_enabled.RTE_CPUFLAG_$flag $dir || echo
RTE_CPUFLAG_$flag check missing in $dir; done; done

RTE_CPUFLAG_AVX512BW check missing in drivers/common/idpf
RTE_CPUFLAG_AVX512DQ check missing in drivers/common/idpf
RTE_CPUFLAG_AVX512F check missing in drivers/common/idpf
RTE_CPUFLAG_AVX512VL check missing in drivers/net/i40e
RTE_CPUFLAG_AVX512VL check missing in drivers/net/ice

Maybe some flags are implictly available... worth a confirmation from
Intel in any case from my pov.

Thanks.

-- 
David Marchand

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Bruce Richardson]

On Mon, Sep 30, 2024 at 05:38:44PM +0200, David Marchand wrote:
> On Fri, Sep 6, 2024 at 4:11 PM Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> > assumed that each pointer was always 8B in size.
> >
> > Bruce Richardson (4):
> >   net/i40e: fix AVX-512 pointer copy on 32-bit
> >   net/ice: fix AVX-512 pointer copy on 32-bit
> >   net/iavf: fix AVX-512 pointer copy on 32-bit
> >   common/idpf: fix AVX-512 pointer copy on 32-bit
> >
> >  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
> >  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
> >  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
> >  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
> >  4 files changed, 28 insertions(+)
> 
> Sorry, not directly related to this series, but as I was checking some
> AVX512 patch, I suspect some drivers are missing runtime checks for
> availability of some AVX512 instructions:
> 
> $ for meson in $(git grep -l __AVX512[^_]*__
> 'drivers/**/meson.build'); do dir=$(dirname $meson); for flag in $(git
> grep -ho __AVX512[^_]*__ $dir | sort -u); do flag=${flag%%__};
> flag=${flag##__}; git grep -ql
> rte_cpu_get_flag_enabled.RTE_CPUFLAG_$flag $dir || echo
> RTE_CPUFLAG_$flag check missing in $dir; done; done
> 
> RTE_CPUFLAG_AVX512BW check missing in drivers/common/idpf
> RTE_CPUFLAG_AVX512DQ check missing in drivers/common/idpf
> RTE_CPUFLAG_AVX512F check missing in drivers/common/idpf
> RTE_CPUFLAG_AVX512VL check missing in drivers/net/i40e
> RTE_CPUFLAG_AVX512VL check missing in drivers/net/ice
> 
> Maybe some flags are implictly available... worth a confirmation from
> Intel in any case from my pov.
> 

I think it would be good practice to explicitly check for all the AVX-512
extensions actually used. Ideally, as a cleanup, we should probably check
for those listed (f, bw, dq and vl) once early in the config and reuse that
value throughout the build, rather than having each and every PMD
continually check them.

/Bruce

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Bruce Richardson]

On Mon, Sep 30, 2024 at 04:57:21PM +0100, Bruce Richardson wrote:
> On Mon, Sep 30, 2024 at 05:38:44PM +0200, David Marchand wrote:
> > On Fri, Sep 6, 2024 at 4:11 PM Bruce Richardson
> > <bruce.richardson@intel.com> wrote:
> > >
> > > The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> > > assumed that each pointer was always 8B in size.
> > >
> > > Bruce Richardson (4):
> > >   net/i40e: fix AVX-512 pointer copy on 32-bit
> > >   net/ice: fix AVX-512 pointer copy on 32-bit
> > >   net/iavf: fix AVX-512 pointer copy on 32-bit
> > >   common/idpf: fix AVX-512 pointer copy on 32-bit
> > >
> > >  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
> > >  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
> > >  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
> > >  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
> > >  4 files changed, 28 insertions(+)
> > 
> > Sorry, not directly related to this series, but as I was checking some
> > AVX512 patch, I suspect some drivers are missing runtime checks for
> > availability of some AVX512 instructions:
> > 
> > $ for meson in $(git grep -l __AVX512[^_]*__
> > 'drivers/**/meson.build'); do dir=$(dirname $meson); for flag in $(git
> > grep -ho __AVX512[^_]*__ $dir | sort -u); do flag=${flag%%__};
> > flag=${flag##__}; git grep -ql
> > rte_cpu_get_flag_enabled.RTE_CPUFLAG_$flag $dir || echo
> > RTE_CPUFLAG_$flag check missing in $dir; done; done
> > 
> > RTE_CPUFLAG_AVX512BW check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512DQ check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512F check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512VL check missing in drivers/net/i40e
> > RTE_CPUFLAG_AVX512VL check missing in drivers/net/ice
> > 
> > Maybe some flags are implictly available... worth a confirmation from
> > Intel in any case from my pov.
> > 
> 
> I think it would be good practice to explicitly check for all the AVX-512
> extensions actually used. Ideally, as a cleanup, we should probably check
> for those listed (f, bw, dq and vl) once early in the config and reuse that
> value throughout the build, rather than having each and every PMD
> continually check them.
> 
Draft patchset for this now submitted to dev list [1]. Reviews and feedback
welcome, as always!

/Bruce

[1] https://patches.dpdk.org/project/dpdk/list/?series=33188

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[David Marchand]

On Mon, Sep 30, 2024 at 5:57 PM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Mon, Sep 30, 2024 at 05:38:44PM +0200, David Marchand wrote:
> > On Fri, Sep 6, 2024 at 4:11 PM Bruce Richardson
> > <bruce.richardson@intel.com> wrote:
> > >
> > > The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> > > assumed that each pointer was always 8B in size.
> > >
> > > Bruce Richardson (4):
> > >   net/i40e: fix AVX-512 pointer copy on 32-bit
> > >   net/ice: fix AVX-512 pointer copy on 32-bit
> > >   net/iavf: fix AVX-512 pointer copy on 32-bit
> > >   common/idpf: fix AVX-512 pointer copy on 32-bit
> > >
> > >  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
> > >  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
> > >  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
> > >  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
> > >  4 files changed, 28 insertions(+)
> >
> > Sorry, not directly related to this series, but as I was checking some
> > AVX512 patch, I suspect some drivers are missing runtime checks for
> > availability of some AVX512 instructions:
> >
> > $ for meson in $(git grep -l __AVX512[^_]*__
> > 'drivers/**/meson.build'); do dir=$(dirname $meson); for flag in $(git
> > grep -ho __AVX512[^_]*__ $dir | sort -u); do flag=${flag%%__};
> > flag=${flag##__}; git grep -ql
> > rte_cpu_get_flag_enabled.RTE_CPUFLAG_$flag $dir || echo
> > RTE_CPUFLAG_$flag check missing in $dir; done; done
> >
> > RTE_CPUFLAG_AVX512BW check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512DQ check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512F check missing in drivers/common/idpf
> > RTE_CPUFLAG_AVX512VL check missing in drivers/net/i40e
> > RTE_CPUFLAG_AVX512VL check missing in drivers/net/ice
> >
> > Maybe some flags are implictly available... worth a confirmation from
> > Intel in any case from my pov.
> >
>
> I think it would be good practice to explicitly check for all the AVX-512
> extensions actually used. Ideally, as a cleanup, we should probably check
> for those listed (f, bw, dq and vl) once early in the config and reuse that
> value throughout the build, rather than having each and every PMD
> continually check them.

This simplification on the build side looks good.

On the other hand, vectorized handlers in libraries and drivers are
selected based on some AVX512 instructions availability at runtime.
Don't we need to validate *runtime* availability of each of those
instructions in each library/driver?


-- 
David Marchand

Re: [PATCH 0/4] fix issues with using AVX-512 drivers on 32-bit

[Bruce Richardson]

On Tue, Oct 01, 2024 at 09:14:53AM +0200, David Marchand wrote:
> On Mon, Sep 30, 2024 at 5:57 PM Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > On Mon, Sep 30, 2024 at 05:38:44PM +0200, David Marchand wrote:
> > > On Fri, Sep 6, 2024 at 4:11 PM Bruce Richardson
> > > <bruce.richardson@intel.com> wrote:
> > > >
> > > > The AVX-512 copy code in multiple drivers was incorrect for 32-bit as it
> > > > assumed that each pointer was always 8B in size.
> > > >
> > > > Bruce Richardson (4):
> > > >   net/i40e: fix AVX-512 pointer copy on 32-bit
> > > >   net/ice: fix AVX-512 pointer copy on 32-bit
> > > >   net/iavf: fix AVX-512 pointer copy on 32-bit
> > > >   common/idpf: fix AVX-512 pointer copy on 32-bit
> > > >
> > > >  drivers/common/idpf/idpf_common_rxtx_avx512.c | 7 +++++++
> > > >  drivers/net/i40e/i40e_rxtx_vec_avx512.c       | 7 +++++++
> > > >  drivers/net/iavf/iavf_rxtx_vec_avx512.c       | 7 +++++++
> > > >  drivers/net/ice/ice_rxtx_vec_avx512.c         | 7 +++++++
> > > >  4 files changed, 28 insertions(+)
> > >
> > > Sorry, not directly related to this series, but as I was checking some
> > > AVX512 patch, I suspect some drivers are missing runtime checks for
> > > availability of some AVX512 instructions:
> > >
> > > $ for meson in $(git grep -l __AVX512[^_]*__
> > > 'drivers/**/meson.build'); do dir=$(dirname $meson); for flag in $(git
> > > grep -ho __AVX512[^_]*__ $dir | sort -u); do flag=${flag%%__};
> > > flag=${flag##__}; git grep -ql
> > > rte_cpu_get_flag_enabled.RTE_CPUFLAG_$flag $dir || echo
> > > RTE_CPUFLAG_$flag check missing in $dir; done; done
> > >
> > > RTE_CPUFLAG_AVX512BW check missing in drivers/common/idpf
> > > RTE_CPUFLAG_AVX512DQ check missing in drivers/common/idpf
> > > RTE_CPUFLAG_AVX512F check missing in drivers/common/idpf
> > > RTE_CPUFLAG_AVX512VL check missing in drivers/net/i40e
> > > RTE_CPUFLAG_AVX512VL check missing in drivers/net/ice
> > >
> > > Maybe some flags are implictly available... worth a confirmation from
> > > Intel in any case from my pov.
> > >
> >
> > I think it would be good practice to explicitly check for all the AVX-512
> > extensions actually used. Ideally, as a cleanup, we should probably check
> > for those listed (f, bw, dq and vl) once early in the config and reuse that
> > value throughout the build, rather than having each and every PMD
> > continually check them.
> 
> This simplification on the build side looks good.
> 
> On the other hand, vectorized handlers in libraries and drivers are
> selected based on some AVX512 instructions availability at runtime.
> Don't we need to validate *runtime* availability of each of those
> instructions in each library/driver?
> 
Yes, each lib and driver should be also checking these at runtime.
Simplification of such checks may be possible, and may be something I look
at in future, time permitting. For now, an example of the checks done can
be seen in [1].

/Bruce

[1] https://git.dpdk.org/dpdk/tree/drivers/net/ice/ice_rxtx.c#n3486