* Re: [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA
[not found] ` <20230912083126.65484-2-linyunsheng@huawei.com>
@ 2023-09-15 8:28 ` Jesper Dangaard Brouer
2023-09-20 8:59 ` Yunsheng Lin
0 siblings, 1 reply; 4+ messages in thread
From: Jesper Dangaard Brouer @ 2023-09-15 8:28 UTC (permalink / raw)
To: Yunsheng Lin, davem, kuba, pabeni
Cc: brouer, netdev, linux-kernel, Lorenzo Bianconi, Alexander Duyck,
Liang Chen, Alexander Lobakin, Guillaume Tucker,
Jesper Dangaard Brouer, Ilias Apalodimas, Eric Dumazet, Linux-MM,
Matthew Wilcox, Mel Gorman
Hi Lin,
This looks reasonable, but given you are changing struct-page
(include/linux/mm_types.h) we need to MM-list <linux-mm@kvack.org>.
Also Cc Wilcox.
I think it was Ilias and Duyck that validated the assumptions, last time
this patch was discussed. Thus I want to see their review before this is
applied.
-Jesper
On 12/09/2023 10.31, Yunsheng Lin wrote:
> Currently page_pool_alloc_frag() is not supported in 32-bit
> arch with 64-bit DMA because of the overlap issue between
> pp_frag_count and dma_addr_upper in 'struct page' for those
> arches, which seems to be quite common, see [1], which means
> driver may need to handle it when using frag API.
>
> It is assumed that the combination of the above arch with an
> address space >16TB does not exist, as all those arches have
> 64b equivalent, it seems logical to use the 64b version for a
> system with a large address space. It is also assumed that dma
> address is page aligned when we are dma mapping a page aliged
> buffer, see [2].
>
> That means we're storing 12 bits of 0 at the lower end for a
> dma address, we can reuse those bits for the above arches to
> support 32b+12b, which is 16TB of memory.
>
> If we make a wrong assumption, a warning is emitted so that
> user can report to us.
>
> 1. https://lore.kernel.org/all/20211117075652.58299-1-linyunsheng@huawei.com/
> 2. https://lore.kernel.org/all/20230818145145.4b357c89@kernel.org/
>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> CC: Lorenzo Bianconi <lorenzo@kernel.org>
> CC: Alexander Duyck <alexander.duyck@gmail.com>
> CC: Liang Chen <liangchen.linux@gmail.com>
> CC: Alexander Lobakin <aleksander.lobakin@intel.com>
> CC: Guillaume Tucker <guillaume.tucker@collabora.com>
> ---
> include/linux/mm_types.h | 13 +------------
> include/net/page_pool/helpers.h | 20 ++++++++++++++------
> net/core/page_pool.c | 14 +++++++++-----
> 3 files changed, 24 insertions(+), 23 deletions(-)
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 36c5b43999e6..74b49c4c7a52 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -125,18 +125,7 @@ struct page {
> struct page_pool *pp;
> unsigned long _pp_mapping_pad;
> unsigned long dma_addr;
> - union {
> - /**
> - * dma_addr_upper: might require a 64-bit
> - * value on 32-bit architectures.
> - */
> - unsigned long dma_addr_upper;
> - /**
> - * For frag page support, not supported in
> - * 32-bit architectures with 64-bit DMA.
> - */
> - atomic_long_t pp_frag_count;
> - };
> + atomic_long_t pp_frag_count;
> };
> struct { /* Tail pages of compound page */
> unsigned long compound_head; /* Bit zero is set */
> diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
> index 94231533a369..8e1c85de4995 100644
> --- a/include/net/page_pool/helpers.h
> +++ b/include/net/page_pool/helpers.h
> @@ -197,7 +197,7 @@ static inline void page_pool_recycle_direct(struct page_pool *pool,
> page_pool_put_full_page(pool, page, true);
> }
>
> -#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \
> +#define PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA \
> (sizeof(dma_addr_t) > sizeof(unsigned long))
>
> /**
> @@ -211,17 +211,25 @@ static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
> {
> dma_addr_t ret = page->dma_addr;
>
> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
> - ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16;
> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
> + ret <<= PAGE_SHIFT;
>
> return ret;
> }
>
> -static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
> +static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
> {
> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
> + page->dma_addr = addr >> PAGE_SHIFT;
> +
> + /* We assume page alignment to shave off bottom bits,
> + * if this "compression" doesn't work we need to drop.
> + */
> + return addr != (dma_addr_t)page->dma_addr << PAGE_SHIFT;
> + }
> +
> page->dma_addr = addr;
> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
> - page->dma_addr_upper = upper_32_bits(addr);
> + return false;
> }
>
> static inline bool page_pool_put(struct page_pool *pool)
> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> index 77cb75e63aca..8a9868ea5067 100644
> --- a/net/core/page_pool.c
> +++ b/net/core/page_pool.c
> @@ -211,10 +211,6 @@ static int page_pool_init(struct page_pool *pool,
> */
> }
>
> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT &&
> - pool->p.flags & PP_FLAG_PAGE_FRAG)
> - return -EINVAL;
> -
> #ifdef CONFIG_PAGE_POOL_STATS
> pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats);
> if (!pool->recycle_stats)
> @@ -359,12 +355,20 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
> if (dma_mapping_error(pool->p.dev, dma))
> return false;
>
> - page_pool_set_dma_addr(page, dma);
> + if (page_pool_set_dma_addr(page, dma))
> + goto unmap_failed;
>
> if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
> page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
>
> return true;
> +
> +unmap_failed:
> + WARN_ON_ONCE("unexpected DMA address, please report to netdev@");
> + dma_unmap_page_attrs(pool->p.dev, dma,
> + PAGE_SIZE << pool->p.order, pool->p.dma_dir,
> + DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
> + return false;
> }
>
> static void page_pool_set_pp_info(struct page_pool *pool,
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA
2023-09-15 8:28 ` [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA Jesper Dangaard Brouer
@ 2023-09-20 8:59 ` Yunsheng Lin
2023-09-25 10:37 ` Ilias Apalodimas
0 siblings, 1 reply; 4+ messages in thread
From: Yunsheng Lin @ 2023-09-20 8:59 UTC (permalink / raw)
To: Jesper Dangaard Brouer, davem, kuba, pabeni
Cc: brouer, netdev, linux-kernel, Lorenzo Bianconi, Alexander Duyck,
Liang Chen, Alexander Lobakin, Guillaume Tucker,
Jesper Dangaard Brouer, Ilias Apalodimas, Eric Dumazet, Linux-MM,
Matthew Wilcox, Mel Gorman
On 2023/9/15 16:28, Jesper Dangaard Brouer wrote:
> Hi Lin,
>
> This looks reasonable, but given you are changing struct-page
> (include/linux/mm_types.h) we need to MM-list <linux-mm@kvack.org>.
> Also Cc Wilcox.
>
> I think it was Ilias and Duyck that validated the assumptions, last time
> this patch was discussed. Thus I want to see their review before this is
> applied.
FWIW, PAGE_SIZE aligned buffer being PAGE_SIZE aligned in DMA is
validated by Duyck:
https://lore.kernel.org/all/CAKgT0UfeUAUQpEffxnkc+gzXsjOrHkuMgxU_Aw0VXSJYKzaovQ@mail.gmail.com/
And I had done researching to find out there seems to be no combination of
the above arch with an address space >16TB:
https://lore.kernel.org/all/2b570282-24f8-f23b-1ff7-ad836794baa9@huawei.com/
>
> -Jesper
>
> On 12/09/2023 10.31, Yunsheng Lin wrote:
>> Currently page_pool_alloc_frag() is not supported in 32-bit
>> arch with 64-bit DMA because of the overlap issue between
>> pp_frag_count and dma_addr_upper in 'struct page' for those
>> arches, which seems to be quite common, see [1], which means
>> driver may need to handle it when using frag API.
>>
>> It is assumed that the combination of the above arch with an
>> address space >16TB does not exist, as all those arches have
>> 64b equivalent, it seems logical to use the 64b version for a
>> system with a large address space. It is also assumed that dma
>> address is page aligned when we are dma mapping a page aliged
>> buffer, see [2].
>>
>> That means we're storing 12 bits of 0 at the lower end for a
>> dma address, we can reuse those bits for the above arches to
>> support 32b+12b, which is 16TB of memory.
>>
>> If we make a wrong assumption, a warning is emitted so that
>> user can report to us.
>>
>> 1. https://lore.kernel.org/all/20211117075652.58299-1-linyunsheng@huawei.com/
>> 2. https://lore.kernel.org/all/20230818145145.4b357c89@kernel.org/
>>
>> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
>> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
>> CC: Lorenzo Bianconi <lorenzo@kernel.org>
>> CC: Alexander Duyck <alexander.duyck@gmail.com>
>> CC: Liang Chen <liangchen.linux@gmail.com>
>> CC: Alexander Lobakin <aleksander.lobakin@intel.com>
>> CC: Guillaume Tucker <guillaume.tucker@collabora.com>
>> ---
>> include/linux/mm_types.h | 13 +------------
>> include/net/page_pool/helpers.h | 20 ++++++++++++++------
>> net/core/page_pool.c | 14 +++++++++-----
>> 3 files changed, 24 insertions(+), 23 deletions(-)
>>
>> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
>> index 36c5b43999e6..74b49c4c7a52 100644
>> --- a/include/linux/mm_types.h
>> +++ b/include/linux/mm_types.h
>> @@ -125,18 +125,7 @@ struct page {
>> struct page_pool *pp;
>> unsigned long _pp_mapping_pad;
>> unsigned long dma_addr;
>> - union {
>> - /**
>> - * dma_addr_upper: might require a 64-bit
>> - * value on 32-bit architectures.
>> - */
>> - unsigned long dma_addr_upper;
>> - /**
>> - * For frag page support, not supported in
>> - * 32-bit architectures with 64-bit DMA.
>> - */
>> - atomic_long_t pp_frag_count;
>> - };
>> + atomic_long_t pp_frag_count;
>> };
>> struct { /* Tail pages of compound page */
>> unsigned long compound_head; /* Bit zero is set */
>> diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
>> index 94231533a369..8e1c85de4995 100644
>> --- a/include/net/page_pool/helpers.h
>> +++ b/include/net/page_pool/helpers.h
>> @@ -197,7 +197,7 @@ static inline void page_pool_recycle_direct(struct page_pool *pool,
>> page_pool_put_full_page(pool, page, true);
>> }
>> -#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \
>> +#define PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA \
>> (sizeof(dma_addr_t) > sizeof(unsigned long))
>> /**
>> @@ -211,17 +211,25 @@ static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
>> {
>> dma_addr_t ret = page->dma_addr;
>> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
>> - ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16;
>> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
>> + ret <<= PAGE_SHIFT;
>> return ret;
>> }
>> -static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
>> +static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
>> {
>> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
>> + page->dma_addr = addr >> PAGE_SHIFT;
>> +
>> + /* We assume page alignment to shave off bottom bits,
>> + * if this "compression" doesn't work we need to drop.
>> + */
>> + return addr != (dma_addr_t)page->dma_addr << PAGE_SHIFT;
>> + }
>> +
>> page->dma_addr = addr;
>> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
>> - page->dma_addr_upper = upper_32_bits(addr);
>> + return false;
>> }
>> static inline bool page_pool_put(struct page_pool *pool)
>> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
>> index 77cb75e63aca..8a9868ea5067 100644
>> --- a/net/core/page_pool.c
>> +++ b/net/core/page_pool.c
>> @@ -211,10 +211,6 @@ static int page_pool_init(struct page_pool *pool,
>> */
>> }
>> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT &&
>> - pool->p.flags & PP_FLAG_PAGE_FRAG)
>> - return -EINVAL;
>> -
>> #ifdef CONFIG_PAGE_POOL_STATS
>> pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats);
>> if (!pool->recycle_stats)
>> @@ -359,12 +355,20 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
>> if (dma_mapping_error(pool->p.dev, dma))
>> return false;
>> - page_pool_set_dma_addr(page, dma);
>> + if (page_pool_set_dma_addr(page, dma))
>> + goto unmap_failed;
>> if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
>> page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
>> return true;
>> +
>> +unmap_failed:
>> + WARN_ON_ONCE("unexpected DMA address, please report to netdev@");
>> + dma_unmap_page_attrs(pool->p.dev, dma,
>> + PAGE_SIZE << pool->p.order, pool->p.dma_dir,
>> + DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
>> + return false;
>> }
>> static void page_pool_set_pp_info(struct page_pool *pool,
>
> .
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA
2023-09-20 8:59 ` Yunsheng Lin
@ 2023-09-25 10:37 ` Ilias Apalodimas
2023-09-25 11:31 ` Yunsheng Lin
0 siblings, 1 reply; 4+ messages in thread
From: Ilias Apalodimas @ 2023-09-25 10:37 UTC (permalink / raw)
To: Yunsheng Lin
Cc: Jesper Dangaard Brouer, davem, kuba, pabeni, brouer, netdev,
linux-kernel, Lorenzo Bianconi, Alexander Duyck, Liang Chen,
Alexander Lobakin, Guillaume Tucker, Jesper Dangaard Brouer,
Eric Dumazet, Linux-MM, Matthew Wilcox, Mel Gorman
Hi
On Wed, 20 Sept 2023 at 11:59, Yunsheng Lin <linyunsheng@huawei.com> wrote:
>
> On 2023/9/15 16:28, Jesper Dangaard Brouer wrote:
> > Hi Lin,
> >
> > This looks reasonable, but given you are changing struct-page
> > (include/linux/mm_types.h) we need to MM-list <linux-mm@kvack.org>.
> > Also Cc Wilcox.
> >
> > I think it was Ilias and Duyck that validated the assumptions, last time
> > this patch was discussed. Thus I want to see their review before this is
> > applied.
>
> FWIW, PAGE_SIZE aligned buffer being PAGE_SIZE aligned in DMA is
> validated by Duyck:
> https://lore.kernel.org/all/CAKgT0UfeUAUQpEffxnkc+gzXsjOrHkuMgxU_Aw0VXSJYKzaovQ@mail.gmail.com/
>
> And I had done researching to find out there seems to be no combination of
> the above arch with an address space >16TB:
> https://lore.kernel.org/all/2b570282-24f8-f23b-1ff7-ad836794baa9@huawei.com/
Apologies for the late reply. I just saw you sent a v9, I'll review
that instead, but I am traveling right now, will take a while
Thanks
/Ilias
>
> >
> > -Jesper
> >
> > On 12/09/2023 10.31, Yunsheng Lin wrote:
> >> Currently page_pool_alloc_frag() is not supported in 32-bit
> >> arch with 64-bit DMA because of the overlap issue between
> >> pp_frag_count and dma_addr_upper in 'struct page' for those
> >> arches, which seems to be quite common, see [1], which means
> >> driver may need to handle it when using frag API.
> >>
> >> It is assumed that the combination of the above arch with an
> >> address space >16TB does not exist, as all those arches have
> >> 64b equivalent, it seems logical to use the 64b version for a
> >> system with a large address space. It is also assumed that dma
> >> address is page aligned when we are dma mapping a page aliged
> >> buffer, see [2].
> >>
> >> That means we're storing 12 bits of 0 at the lower end for a
> >> dma address, we can reuse those bits for the above arches to
> >> support 32b+12b, which is 16TB of memory.
> >>
> >> If we make a wrong assumption, a warning is emitted so that
> >> user can report to us.
> >>
> >> 1. https://lore.kernel.org/all/20211117075652.58299-1-linyunsheng@huawei.com/
> >> 2. https://lore.kernel.org/all/20230818145145.4b357c89@kernel.org/
> >>
> >> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> >> Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
> >> CC: Lorenzo Bianconi <lorenzo@kernel.org>
> >> CC: Alexander Duyck <alexander.duyck@gmail.com>
> >> CC: Liang Chen <liangchen.linux@gmail.com>
> >> CC: Alexander Lobakin <aleksander.lobakin@intel.com>
> >> CC: Guillaume Tucker <guillaume.tucker@collabora.com>
> >> ---
> >> include/linux/mm_types.h | 13 +------------
> >> include/net/page_pool/helpers.h | 20 ++++++++++++++------
> >> net/core/page_pool.c | 14 +++++++++-----
> >> 3 files changed, 24 insertions(+), 23 deletions(-)
> >>
> >> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> >> index 36c5b43999e6..74b49c4c7a52 100644
> >> --- a/include/linux/mm_types.h
> >> +++ b/include/linux/mm_types.h
> >> @@ -125,18 +125,7 @@ struct page {
> >> struct page_pool *pp;
> >> unsigned long _pp_mapping_pad;
> >> unsigned long dma_addr;
> >> - union {
> >> - /**
> >> - * dma_addr_upper: might require a 64-bit
> >> - * value on 32-bit architectures.
> >> - */
> >> - unsigned long dma_addr_upper;
> >> - /**
> >> - * For frag page support, not supported in
> >> - * 32-bit architectures with 64-bit DMA.
> >> - */
> >> - atomic_long_t pp_frag_count;
> >> - };
> >> + atomic_long_t pp_frag_count;
> >> };
> >> struct { /* Tail pages of compound page */
> >> unsigned long compound_head; /* Bit zero is set */
> >> diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
> >> index 94231533a369..8e1c85de4995 100644
> >> --- a/include/net/page_pool/helpers.h
> >> +++ b/include/net/page_pool/helpers.h
> >> @@ -197,7 +197,7 @@ static inline void page_pool_recycle_direct(struct page_pool *pool,
> >> page_pool_put_full_page(pool, page, true);
> >> }
> >> -#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \
> >> +#define PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA \
> >> (sizeof(dma_addr_t) > sizeof(unsigned long))
> >> /**
> >> @@ -211,17 +211,25 @@ static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
> >> {
> >> dma_addr_t ret = page->dma_addr;
> >> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
> >> - ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16;
> >> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
> >> + ret <<= PAGE_SHIFT;
> >> return ret;
> >> }
> >> -static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
> >> +static inline bool page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
> >> {
> >> + if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA) {
> >> + page->dma_addr = addr >> PAGE_SHIFT;
> >> +
> >> + /* We assume page alignment to shave off bottom bits,
> >> + * if this "compression" doesn't work we need to drop.
> >> + */
> >> + return addr != (dma_addr_t)page->dma_addr << PAGE_SHIFT;
> >> + }
> >> +
> >> page->dma_addr = addr;
> >> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
> >> - page->dma_addr_upper = upper_32_bits(addr);
> >> + return false;
> >> }
> >> static inline bool page_pool_put(struct page_pool *pool)
> >> diff --git a/net/core/page_pool.c b/net/core/page_pool.c
> >> index 77cb75e63aca..8a9868ea5067 100644
> >> --- a/net/core/page_pool.c
> >> +++ b/net/core/page_pool.c
> >> @@ -211,10 +211,6 @@ static int page_pool_init(struct page_pool *pool,
> >> */
> >> }
> >> - if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT &&
> >> - pool->p.flags & PP_FLAG_PAGE_FRAG)
> >> - return -EINVAL;
> >> -
> >> #ifdef CONFIG_PAGE_POOL_STATS
> >> pool->recycle_stats = alloc_percpu(struct page_pool_recycle_stats);
> >> if (!pool->recycle_stats)
> >> @@ -359,12 +355,20 @@ static bool page_pool_dma_map(struct page_pool *pool, struct page *page)
> >> if (dma_mapping_error(pool->p.dev, dma))
> >> return false;
> >> - page_pool_set_dma_addr(page, dma);
> >> + if (page_pool_set_dma_addr(page, dma))
> >> + goto unmap_failed;
> >> if (pool->p.flags & PP_FLAG_DMA_SYNC_DEV)
> >> page_pool_dma_sync_for_device(pool, page, pool->p.max_len);
> >> return true;
> >> +
> >> +unmap_failed:
> >> + WARN_ON_ONCE("unexpected DMA address, please report to netdev@");
> >> + dma_unmap_page_attrs(pool->p.dev, dma,
> >> + PAGE_SIZE << pool->p.order, pool->p.dma_dir,
> >> + DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_WEAK_ORDERING);
> >> + return false;
> >> }
> >> static void page_pool_set_pp_info(struct page_pool *pool,
> >
> > .
> >
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA
2023-09-25 10:37 ` Ilias Apalodimas
@ 2023-09-25 11:31 ` Yunsheng Lin
0 siblings, 0 replies; 4+ messages in thread
From: Yunsheng Lin @ 2023-09-25 11:31 UTC (permalink / raw)
To: Ilias Apalodimas
Cc: Jesper Dangaard Brouer, davem, kuba, pabeni, brouer, netdev,
linux-kernel, Lorenzo Bianconi, Alexander Duyck, Liang Chen,
Alexander Lobakin, Guillaume Tucker, Jesper Dangaard Brouer,
Eric Dumazet, Linux-MM, Matthew Wilcox, Mel Gorman
On 2023/9/25 18:37, Ilias Apalodimas wrote:
> Hi
>
> On Wed, 20 Sept 2023 at 11:59, Yunsheng Lin <linyunsheng@huawei.com> wrote:
>>
>> On 2023/9/15 16:28, Jesper Dangaard Brouer wrote:
>>> Hi Lin,
>>>
>>> This looks reasonable, but given you are changing struct-page
>>> (include/linux/mm_types.h) we need to MM-list <linux-mm@kvack.org>.
>>> Also Cc Wilcox.
>>>
>>> I think it was Ilias and Duyck that validated the assumptions, last time
>>> this patch was discussed. Thus I want to see their review before this is
>>> applied.
>>
>> FWIW, PAGE_SIZE aligned buffer being PAGE_SIZE aligned in DMA is
>> validated by Duyck:
>> https://lore.kernel.org/all/CAKgT0UfeUAUQpEffxnkc+gzXsjOrHkuMgxU_Aw0VXSJYKzaovQ@mail.gmail.com/
>>
>> And I had done researching to find out there seems to be no combination of
>> the above arch with an address space >16TB:
>> https://lore.kernel.org/all/2b570282-24f8-f23b-1ff7-ad836794baa9@huawei.com/
>
> Apologies for the late reply. I just saw you sent a v9, I'll review
> that instead, but I am traveling right now, will take a while
Actually there is a newer v10, see:
https://lore.kernel.org/all/20230922091138.18014-2-linyunsheng@huawei.com/
Thanks for the time reviewing.
>
> Thanks
> /Ilias
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-09-15 8:28 ` [PATCH net-next v8 1/6] page_pool: frag API support for 32-bit arch with 64-bit DMA Jesper Dangaard Brouer
2023-09-20 8:59 ` Yunsheng Lin
2023-09-25 10:37 ` Ilias Apalodimas
2023-09-25 11:31 ` Yunsheng Lin
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