| Message ID | 1379064655-20874-2-git-send-email-tangchen@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Hi Tang, On 2013/9/13 17:30, Tang Chen wrote: > The Linux kernel cannot migrate pages used by the kernel. As a result, kernel > pages cannot be hot-removed. So we cannot allocate hotpluggable memory for > the kernel. > > ACPI SRAT (System Resource Affinity Table) contains the memory hotplug info. > But before SRAT is parsed, memblock has already started to allocate memory > for the kernel. So we need to prevent memblock from doing this. > > In a memory hotplug system, any numa node the kernel resides in should > be unhotpluggable. And for a modern server, each node could have at least > 16GB memory. So memory around the kernel image is highly likely unhotpluggable. > > So the basic idea is: Allocate memory from the end of the kernel image and > to the higher memory. Since memory allocation before SRAT is parsed won't > be too much, it could highly likely be in the same node with kernel image. > > The current memblock can only allocate memory from high address to low. > So this patch introduces the allocation direct to memblock. It could be > used to tell memblock to allocate memory from high to low or from low > to high. > > Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> > Reviewed-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com> > --- > include/linux/memblock.h | 22 ++++++++++++++++++++++ > mm/memblock.c | 13 +++++++++++++ > 2 files changed, 35 insertions(+), 0 deletions(-) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 31e95ac..a7d3436 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -19,6 +19,11 @@ > > #define INIT_MEMBLOCK_REGIONS 128 > > +/* Allocation order. */ s/order/direction/ > +#define MEMBLOCK_DIRECTION_HIGH_TO_LOW 0 > +#define MEMBLOCK_DIRECTION_LOW_TO_HIGH 1 > +#define MEMBLOCK_DIRECTION_DEFAULT MEMBLOCK_DIRECTION_HIGH_TO_LOW > + > struct memblock_region { > phys_addr_t base; > phys_addr_t size; > @@ -35,6 +40,7 @@ struct memblock_type { > }; > > struct memblock { > + int current_direction; /* allocate from higher or lower address */ > phys_addr_t current_limit; > struct memblock_type memory; > struct memblock_type reserved; > @@ -148,6 +154,12 @@ phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid) > > phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align); > > +static inline bool memblock_direction_bottom_up(void) > +{ > + return memblock.current_direction == MEMBLOCK_DIRECTION_LOW_TO_HIGH; > +} > + > + > /* Flags for memblock_alloc_base() amd __memblock_alloc_base() */ > #define MEMBLOCK_ALLOC_ANYWHERE (~(phys_addr_t)0) > #define MEMBLOCK_ALLOC_ACCESSIBLE 0 > @@ -175,6 +187,16 @@ static inline void memblock_dump_all(void) > } > > /** > + * memblock_set_current_direction - Set current allocation direction to allow > + * allocating memory from higher to lower > + * address or from lower to higher address > + * > + * @direction: In which order to allocate memory. Could be s/order/direction/ > + * MEMBLOCK_DIRECTION_{HIGH_TO_LOW|LOW_TO_HIGH} > + */ > +void memblock_set_current_direction(int direction); > + > +/** > * memblock_set_current_limit - Set the current allocation limit to allow > * limiting allocations to what is currently > * accessible during boot > diff --git a/mm/memblock.c b/mm/memblock.c > index 0ac412a..f24ca2e 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -32,6 +32,7 @@ struct memblock memblock __initdata_memblock = { > .reserved.cnt = 1, /* empty dummy entry */ > .reserved.max = INIT_MEMBLOCK_REGIONS, > > + .current_direction = MEMBLOCK_DIRECTION_DEFAULT, > .current_limit = MEMBLOCK_ALLOC_ANYWHERE, > }; > > @@ -995,6 +996,18 @@ void __init_memblock memblock_trim_memory(phys_addr_t align) > } > } > > +void __init_memblock memblock_set_current_direction(int direction) > +{ > + if (direction != MEMBLOCK_DIRECTION_HIGH_TO_LOW && > + direction != MEMBLOCK_DIRECTION_LOW_TO_HIGH) { > + pr_warn("memblock: Failed to set allocation order. " > + "Invalid order type: %d\n", direction); s/order/direction/ > + return; > + } > + > + memblock.current_direction = direction; > +} > + > void __init_memblock memblock_set_current_limit(phys_addr_t limit) > { > memblock.current_limit = limit; -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, Sorry about the delay. Was traveling. On Fri, Sep 13, 2013 at 05:30:51PM +0800, Tang Chen wrote: > +/* Allocation order. */ > +#define MEMBLOCK_DIRECTION_HIGH_TO_LOW 0 > +#define MEMBLOCK_DIRECTION_LOW_TO_HIGH 1 > +#define MEMBLOCK_DIRECTION_DEFAULT MEMBLOCK_DIRECTION_HIGH_TO_LOW Can we please settle on either top_down/bottom_up or high_to_low/low_to_high? The two seem to be used interchangeably in the patch series. Also, it'd be more customary to use enum for things like above, but more on the interface below. > +static inline bool memblock_direction_bottom_up(void) > +{ > + return memblock.current_direction == MEMBLOCK_DIRECTION_LOW_TO_HIGH; > +} Maybe just memblock_bottom_up() would be enough? Also, why not also have memblock_set_bottom_up(bool enable) as the 'set' interface? > /** > + * memblock_set_current_direction - Set current allocation direction to allow > + * allocating memory from higher to lower > + * address or from lower to higher address > + * > + * @direction: In which order to allocate memory. Could be > + * MEMBLOCK_DIRECTION_{HIGH_TO_LOW|LOW_TO_HIGH} > + */ > +void memblock_set_current_direction(int direction); Function comments should go with the function definition. Dunno what happened with set_current_limit but let's please not spread it. > +void __init_memblock memblock_set_current_direction(int direction) > +{ > + if (direction != MEMBLOCK_DIRECTION_HIGH_TO_LOW && > + direction != MEMBLOCK_DIRECTION_LOW_TO_HIGH) { > + pr_warn("memblock: Failed to set allocation order. " > + "Invalid order type: %d\n", direction); > + return; > + } > + > + memblock.current_direction = direction; > +} If set_bottom_up() style interface is used, the above will be a lot simpler, right? Also, it's kinda weird to have two separate patches to introduce the flag and actually implement bottom up allocation. Thanks.
Hello tejun, On 09/23/2013 11:38 PM, Tejun Heo wrote: > Hello, > > Sorry about the delay. Was traveling. hoho~ I guess you did have a good time. > > On Fri, Sep 13, 2013 at 05:30:51PM +0800, Tang Chen wrote: >> +/* Allocation order. */ >> +#define MEMBLOCK_DIRECTION_HIGH_TO_LOW 0 >> +#define MEMBLOCK_DIRECTION_LOW_TO_HIGH 1 >> +#define MEMBLOCK_DIRECTION_DEFAULT MEMBLOCK_DIRECTION_HIGH_TO_LOW > > Can we please settle on either top_down/bottom_up or > high_to_low/low_to_high? The two seem to be used interchangeably in > the patch series. Also, it'd be more customary to use enum for things > like above, but more on the interface below. OK. let's use top_down/bottom_up. And using enum is also ok. > >> +static inline bool memblock_direction_bottom_up(void) >> +{ >> + return memblock.current_direction == MEMBLOCK_DIRECTION_LOW_TO_HIGH; >> +} > > Maybe just memblock_bottom_up() would be enough? Agreed. > > Also, why not also have memblock_set_bottom_up(bool enable) as the > 'set' interface? hmmm, ok. So we will use memblock_set_bottom_up to replace memblock_set_current_direction below. > >> /** >> + * memblock_set_current_direction - Set current allocation direction to allow >> + * allocating memory from higher to lower >> + * address or from lower to higher address >> + * >> + * @direction: In which order to allocate memory. Could be >> + * MEMBLOCK_DIRECTION_{HIGH_TO_LOW|LOW_TO_HIGH} >> + */ >> +void memblock_set_current_direction(int direction); > > Function comments should go with the function definition. Dunno what > happened with set_current_limit but let's please not spread it. > >> +void __init_memblock memblock_set_current_direction(int direction) >> +{ >> + if (direction != MEMBLOCK_DIRECTION_HIGH_TO_LOW && >> + direction != MEMBLOCK_DIRECTION_LOW_TO_HIGH) { >> + pr_warn("memblock: Failed to set allocation order. " >> + "Invalid order type: %d\n", direction); >> + return; >> + } >> + >> + memblock.current_direction = direction; >> +} > > If set_bottom_up() style interface is used, the above will be a lot > simpler, right? Also, it's kinda weird to have two separate patches > to introduce the flag and actually implement bottom up allocation. Yeah, right, that'd be much simpler. And it is ok to put the two in one patch. Thanks. > > Thanks. >
diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 31e95ac..a7d3436 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -19,6 +19,11 @@ #define INIT_MEMBLOCK_REGIONS 128 +/* Allocation order. */ +#define MEMBLOCK_DIRECTION_HIGH_TO_LOW 0 +#define MEMBLOCK_DIRECTION_LOW_TO_HIGH 1 +#define MEMBLOCK_DIRECTION_DEFAULT MEMBLOCK_DIRECTION_HIGH_TO_LOW + struct memblock_region { phys_addr_t base; phys_addr_t size; @@ -35,6 +40,7 @@ struct memblock_type { }; struct memblock { + int current_direction; /* allocate from higher or lower address */ phys_addr_t current_limit; struct memblock_type memory; struct memblock_type reserved; @@ -148,6 +154,12 @@ phys_addr_t memblock_alloc_try_nid(phys_addr_t size, phys_addr_t align, int nid) phys_addr_t memblock_alloc(phys_addr_t size, phys_addr_t align); +static inline bool memblock_direction_bottom_up(void) +{ + return memblock.current_direction == MEMBLOCK_DIRECTION_LOW_TO_HIGH; +} + + /* Flags for memblock_alloc_base() amd __memblock_alloc_base() */ #define MEMBLOCK_ALLOC_ANYWHERE (~(phys_addr_t)0) #define MEMBLOCK_ALLOC_ACCESSIBLE 0 @@ -175,6 +187,16 @@ static inline void memblock_dump_all(void) } /** + * memblock_set_current_direction - Set current allocation direction to allow + * allocating memory from higher to lower + * address or from lower to higher address + * + * @direction: In which order to allocate memory. Could be + * MEMBLOCK_DIRECTION_{HIGH_TO_LOW|LOW_TO_HIGH} + */ +void memblock_set_current_direction(int direction); + +/** * memblock_set_current_limit - Set the current allocation limit to allow * limiting allocations to what is currently * accessible during boot diff --git a/mm/memblock.c b/mm/memblock.c index 0ac412a..f24ca2e 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -32,6 +32,7 @@ struct memblock memblock __initdata_memblock = { .reserved.cnt = 1, /* empty dummy entry */ .reserved.max = INIT_MEMBLOCK_REGIONS, + .current_direction = MEMBLOCK_DIRECTION_DEFAULT, .current_limit = MEMBLOCK_ALLOC_ANYWHERE, }; @@ -995,6 +996,18 @@ void __init_memblock memblock_trim_memory(phys_addr_t align) } } +void __init_memblock memblock_set_current_direction(int direction) +{ + if (direction != MEMBLOCK_DIRECTION_HIGH_TO_LOW && + direction != MEMBLOCK_DIRECTION_LOW_TO_HIGH) { + pr_warn("memblock: Failed to set allocation order. " + "Invalid order type: %d\n", direction); + return; + } + + memblock.current_direction = direction; +} + void __init_memblock memblock_set_current_limit(phys_addr_t limit) { memblock.current_limit = limit;