Re: [PATCH] PCI: Equalize hotplug memory for non/occupied slots
On Wed, Jul 25, 2018 at 05:02:59PM -0600, Jon Derrick wrote:
> Currently, a hotplug bridge will be given hpmemsize additional memory if
> available, in order to satisfy any future hotplug allocation
> requirements.
>
> These calculations don't consider the current memory size of the hotplug
> bridge/slot, so hotplug bridges/slots which have downstream devices will
> get their current allocation in addition to the hpmemsize value.
>
> This makes for possibly undesirable results with a mix of unoccupied and
> occupied slots (ex, with hpmemsize=2M):
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d64f [size=3M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d650-d66f [size=2M]
>
> This change considers the current allocation size when using the
> hpmemsize parameter to make the reservations predictable for the mix of
> unoccupied and occupied slots:
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d63f [size=2M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d640-d65f [size=2M]
The I/O sizing code (pbus_size_io() and calculate_iosize()) is essentially
identical to the mem sizing code you're updating. I assume the same
considerations would apply there? If not, please include a note in the
changelog about why you changed the mem code but not the I/O code.
> Signed-off-by: Jon Derrick
> ---
> Original RFC here:
> https://patchwork.ozlabs.org/patch/945374/
>
> I split this bit out from the RFC while awaiting the pci string handling
> enhancements to handle per-device settings
>
> Changed from RFC is a simpler algo
>
> drivers/pci/setup-bus.c | 13 ++---
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 79b1824..5ae39e6 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -831,7 +831,8 @@ static resource_size_t calculate_iosize(resource_size_t
> size,
>
> static resource_size_t calculate_memsize(resource_size_t size,
> resource_size_t min_size,
> - resource_size_t size1,
> + resource_size_t add_size,
> + resource_size_t children_add_size,
> resource_size_t old_size,
> resource_size_t align)
> {
> @@ -841,7 +842,7 @@ static resource_size_t calculate_memsize(resource_size_t
> size,
> old_size = 0;
> if (size < old_size)
> size = old_size;
> - size = ALIGN(size + size1, align);
> + size = ALIGN(max(size, add_size) + children_add_size, align);
> return size;
> }
>
> @@ -1079,12 +1080,10 @@ static int pbus_size_mem(struct pci_bus *bus,
> unsigned long mask,
>
> min_align = calculate_mem_align(aligns, max_order);
> min_align = max(min_align, window_alignment(bus, b_res->flags));
> - size0 = calculate_memsize(size, min_size, 0, resource_size(b_res),
> min_align);
> + size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res),
> min_align);
> add_align = max(min_align, add_align);
> - if (children_add_size > add_size)
> - add_size = children_add_size;
> - size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
> - calculate_memsize(size, min_size, add_size,
> + size1 = (!realloc_head || (realloc_head && !add_size &&
> !children_add_size)) ? size0 :
> + calculate_memsize(size, min_size, add_size, children_add_size,
> resource_size(b_res), add_align);
> if (!size0 && !size1) {
> if (b_res->start || b_res->end)
> --
> 1.8.3.1
>
Re: [PATCH] PCI: Equalize hotplug memory for non/occupied slots
On Wed, Jul 25, 2018 at 05:02:59PM -0600, Jon Derrick wrote:
> Currently, a hotplug bridge will be given hpmemsize additional memory if
> available, in order to satisfy any future hotplug allocation
> requirements.
>
> These calculations don't consider the current memory size of the hotplug
> bridge/slot, so hotplug bridges/slots which have downstream devices will
> get their current allocation in addition to the hpmemsize value.
>
> This makes for possibly undesirable results with a mix of unoccupied and
> occupied slots (ex, with hpmemsize=2M):
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d64f [size=3M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d650-d66f [size=2M]
>
> This change considers the current allocation size when using the
> hpmemsize parameter to make the reservations predictable for the mix of
> unoccupied and occupied slots:
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d63f [size=2M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d640-d65f [size=2M]
The I/O sizing code (pbus_size_io() and calculate_iosize()) is essentially
identical to the mem sizing code you're updating. I assume the same
considerations would apply there? If not, please include a note in the
changelog about why you changed the mem code but not the I/O code.
> Signed-off-by: Jon Derrick
> ---
> Original RFC here:
> https://patchwork.ozlabs.org/patch/945374/
>
> I split this bit out from the RFC while awaiting the pci string handling
> enhancements to handle per-device settings
>
> Changed from RFC is a simpler algo
>
> drivers/pci/setup-bus.c | 13 ++---
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 79b1824..5ae39e6 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -831,7 +831,8 @@ static resource_size_t calculate_iosize(resource_size_t
> size,
>
> static resource_size_t calculate_memsize(resource_size_t size,
> resource_size_t min_size,
> - resource_size_t size1,
> + resource_size_t add_size,
> + resource_size_t children_add_size,
> resource_size_t old_size,
> resource_size_t align)
> {
> @@ -841,7 +842,7 @@ static resource_size_t calculate_memsize(resource_size_t
> size,
> old_size = 0;
> if (size < old_size)
> size = old_size;
> - size = ALIGN(size + size1, align);
> + size = ALIGN(max(size, add_size) + children_add_size, align);
> return size;
> }
>
> @@ -1079,12 +1080,10 @@ static int pbus_size_mem(struct pci_bus *bus,
> unsigned long mask,
>
> min_align = calculate_mem_align(aligns, max_order);
> min_align = max(min_align, window_alignment(bus, b_res->flags));
> - size0 = calculate_memsize(size, min_size, 0, resource_size(b_res),
> min_align);
> + size0 = calculate_memsize(size, min_size, 0, 0, resource_size(b_res),
> min_align);
> add_align = max(min_align, add_align);
> - if (children_add_size > add_size)
> - add_size = children_add_size;
> - size1 = (!realloc_head || (realloc_head && !add_size)) ? size0 :
> - calculate_memsize(size, min_size, add_size,
> + size1 = (!realloc_head || (realloc_head && !add_size &&
> !children_add_size)) ? size0 :
> + calculate_memsize(size, min_size, add_size, children_add_size,
> resource_size(b_res), add_align);
> if (!size0 && !size1) {
> if (b_res->start || b_res->end)
> --
> 1.8.3.1
>
Re: [PATCH] PCI: Equalize hotplug memory for non/occupied slots
It's been a few weeks. Thoughts on this one?
On Wed, 2018-07-25 at 17:02 -0600, Jon Derrick wrote:
> Currently, a hotplug bridge will be given hpmemsize additional memory
> if
> available, in order to satisfy any future hotplug allocation
> requirements.
>
> These calculations don't consider the current memory size of the
> hotplug
> bridge/slot, so hotplug bridges/slots which have downstream devices
> will
> get their current allocation in addition to the hpmemsize value.
>
> This makes for possibly undesirable results with a mix of unoccupied
> and
> occupied slots (ex, with hpmemsize=2M):
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d64f [size=3M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d650-d66f [size=2M]
>
> This change considers the current allocation size when using the
> hpmemsize parameter to make the reservations predictable for the mix
> of
> unoccupied and occupied slots:
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d63f [size=2M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d640-d65f [size=2M]
>
> Signed-off-by: Jon Derrick
> ---
> Original RFC here:
> https://patchwork.ozlabs.org/patch/945374/
>
> I split this bit out from the RFC while awaiting the pci string
> handling
> enhancements to handle per-device settings
>
> Changed from RFC is a simpler algo
>
> drivers/pci/setup-bus.c | 13 ++---
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 79b1824..5ae39e6 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -831,7 +831,8 @@ static resource_size_t
> calculate_iosize(resource_size_t size,
>
> static resource_size_t calculate_memsize(resource_size_t size,
> resource_size_t min_size,
> - resource_size_t size1,
> + resource_size_t add_size,
> + resource_size_t children_add_size,
> resource_size_t old_size,
> resource_size_t align)
> {
> @@ -841,7 +842,7 @@ static resource_size_t
> calculate_memsize(resource_size_t size,
> old_size = 0;
> if (size < old_size)
> size = old_size;
> - size = ALIGN(size + size1, align);
> + size = ALIGN(max(size, add_size) + children_add_size,
> align);
> return size;
> }
>
> @@ -1079,12 +1080,10 @@ static int pbus_size_mem(struct pci_bus *bus,
> unsigned long mask,
>
> min_align = calculate_mem_align(aligns, max_order);
> min_align = max(min_align, window_alignment(bus, b_res-
> >flags));
> - size0 = calculate_memsize(size, min_size, 0,
> resource_size(b_res), min_align);
> + size0 = calculate_memsize(size, min_size, 0, 0,
> resource_size(b_res), min_align);
> add_align = max(min_align, add_align);
> - if (children_add_size > add_size)
> - add_size = children_add_size;
> - size1 = (!realloc_head || (realloc_head && !add_size)) ?
> size0 :
> - calculate_memsize(size, min_size, add_size,
> + size1 = (!realloc_head || (realloc_head && !add_size &&
> !children_add_size)) ? size0 :
> + calculate_memsize(size, min_size, add_size,
> children_add_size,
> resource_size(b_res), add_align);
> if (!size0 && !size1) {
> if (b_res->start || b_res->end)
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Re: [PATCH] PCI: Equalize hotplug memory for non/occupied slots
It's been a few weeks. Thoughts on this one?
On Wed, 2018-07-25 at 17:02 -0600, Jon Derrick wrote:
> Currently, a hotplug bridge will be given hpmemsize additional memory
> if
> available, in order to satisfy any future hotplug allocation
> requirements.
>
> These calculations don't consider the current memory size of the
> hotplug
> bridge/slot, so hotplug bridges/slots which have downstream devices
> will
> get their current allocation in addition to the hpmemsize value.
>
> This makes for possibly undesirable results with a mix of unoccupied
> and
> occupied slots (ex, with hpmemsize=2M):
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d64f [size=3M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d650-d66f [size=2M]
>
> This change considers the current allocation size when using the
> hpmemsize parameter to make the reservations predictable for the mix
> of
> unoccupied and occupied slots:
>
> 02:03.0 PCI bridge: <-- Occupied
> Memory behind bridge: d620-d63f [size=2M]
> 02:04.0 PCI bridge: <-- Unoccupied
> Memory behind bridge: d640-d65f [size=2M]
>
> Signed-off-by: Jon Derrick
> ---
> Original RFC here:
> https://patchwork.ozlabs.org/patch/945374/
>
> I split this bit out from the RFC while awaiting the pci string
> handling
> enhancements to handle per-device settings
>
> Changed from RFC is a simpler algo
>
> drivers/pci/setup-bus.c | 13 ++---
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 79b1824..5ae39e6 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -831,7 +831,8 @@ static resource_size_t
> calculate_iosize(resource_size_t size,
>
> static resource_size_t calculate_memsize(resource_size_t size,
> resource_size_t min_size,
> - resource_size_t size1,
> + resource_size_t add_size,
> + resource_size_t children_add_size,
> resource_size_t old_size,
> resource_size_t align)
> {
> @@ -841,7 +842,7 @@ static resource_size_t
> calculate_memsize(resource_size_t size,
> old_size = 0;
> if (size < old_size)
> size = old_size;
> - size = ALIGN(size + size1, align);
> + size = ALIGN(max(size, add_size) + children_add_size,
> align);
> return size;
> }
>
> @@ -1079,12 +1080,10 @@ static int pbus_size_mem(struct pci_bus *bus,
> unsigned long mask,
>
> min_align = calculate_mem_align(aligns, max_order);
> min_align = max(min_align, window_alignment(bus, b_res-
> >flags));
> - size0 = calculate_memsize(size, min_size, 0,
> resource_size(b_res), min_align);
> + size0 = calculate_memsize(size, min_size, 0, 0,
> resource_size(b_res), min_align);
> add_align = max(min_align, add_align);
> - if (children_add_size > add_size)
> - add_size = children_add_size;
> - size1 = (!realloc_head || (realloc_head && !add_size)) ?
> size0 :
> - calculate_memsize(size, min_size, add_size,
> + size1 = (!realloc_head || (realloc_head && !add_size &&
> !children_add_size)) ? size0 :
> + calculate_memsize(size, min_size, add_size,
> children_add_size,
> resource_size(b_res), add_align);
> if (!size0 && !size1) {
> if (b_res->start || b_res->end)
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