Messages in this thread | | | Date | Thu, 5 Dec 2013 15:34:31 -0500 | From | Santosh Shilimkar <> | Subject | Re: [PATCH v2 08/23] mm/memblock: Add memblock memory allocation apis |
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Grygorii,
On Thursday 05 December 2013 01:48 PM, Strashko, Grygorii wrote: > Hi Tejun, > >> On Thu, Dec 05, 2013 at 06:35:00PM +0200, Grygorii Strashko wrote: >>>>> +#define memblock_virt_alloc_align(x, align) \ >>>>> + memblock_virt_alloc_try_nid(x, align, BOOTMEM_LOW_LIMIT, \ >>>>> + BOOTMEM_ALLOC_ACCESSIBLE, MAX_NUMNODES) >>>> >>>> Also, do we really need this align variant separate when the caller >>>> can simply specify 0 for the default? >>> >>> Unfortunately Yes. >>> We need it to keep compatibility with bootmem/nobootmem >>> which don't handle 0 as default align value. >> >> Hmm... why wouldn't just interpreting 0 to SMP_CACHE_BYTES in the >> memblock_virt*() function work? >> > > Problem is not with memblock_virt*(). The issue will happen in case if > memblock or nobootmem are disabled in below code (memblock_virt*() is disabled). > > +/* Fall back to all the existing bootmem APIs */ > +#define memblock_virt_alloc(x) \ > + __alloc_bootmem(x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT) > > which will be transformed to > +/* Fall back to all the existing bootmem APIs */ > +#define memblock_virt_alloc(x, align) \ > + __alloc_bootmem(x, align, BOOTMEM_LOW_LIMIT) > > and used as > > memblock_virt_alloc(size, 0); > > so, by default bootmem code will use 0 as default alignment and not SMP_CACHE_BYTES > and that is wrong. > Looks like you didn't understood the suggestion completely. The fall back inline will look like below .....
static inline memblock_virt_alloc(x, align) { if (align == 0) align = SMP_CACHE_BYTES __alloc_bootmem(x, align, BOOTMEM_LOW_LIMIT); }
regards, Santosh
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