[PATCH v2 1/2] dma-direct: provide the ability to reserve per-numa CMA

kernel test robot lkp at intel.com
Sun Jun 28 04:58:40 EDT 2020


Hi Barry,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.8-rc2 next-20200625]
[cannot apply to arm64/for-next/core hch-configfs/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use  as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Barry-Song/make-dma_alloc_coherent-NUMA-aware-by-per-NUMA-CMA/20200625-154656
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 8be3a53e18e0e1a98f288f6c7f5e9da3adbe9c49
config: x86_64-randconfig-s022-20200624 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=x86_64 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp at intel.com>


sparse warnings: (new ones prefixed by >>)

>> kernel/dma/contiguous.c:283:50: sparse: sparse: invalid access below 'dma_contiguous_pernuma_area' (-8 8)

# https://github.com/0day-ci/linux/commit/d6930169a3364418b985c2d19c31ecf1c4c3d4a9
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout d6930169a3364418b985c2d19c31ecf1c4c3d4a9
vim +/dma_contiguous_pernuma_area +283 kernel/dma/contiguous.c

de9e14eebf33a6 drivers/base/dma-contiguous.c Marek Szyprowski  2014-10-13  253  
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  254  /**
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  255   * dma_alloc_contiguous() - allocate contiguous pages
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  256   * @dev:   Pointer to device for which the allocation is performed.
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  257   * @size:  Requested allocation size.
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  258   * @gfp:   Allocation flags.
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  259   *
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  260   * This function allocates contiguous memory buffer for specified device. It
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  261   * tries to use device specific contiguous memory area if available, or it
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  262   * tries to use per-numa cma, if the allocation fails, it will fallback to
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  263   * try default global one.
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  264   *
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  265   * Note that it bypass one-page size of allocations from the per-numa and
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  266   * global area as the addresses within one page are always contiguous, so
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  267   * there is no need to waste CMA pages for that kind; it also helps reduce
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  268   * fragmentations.
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  269   */
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  270  struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  271  {
90ae409f9eb3bc kernel/dma/contiguous.c       Christoph Hellwig 2019-08-20  272  	size_t count = size >> PAGE_SHIFT;
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  273  	struct page *page = NULL;
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  274  	struct cma *cma = NULL;
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  275  	int nid = dev ? dev_to_node(dev) : NUMA_NO_NODE;
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  276  	bool alloc_from_pernuma = false;
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  277  
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  278  	if (dev && dev->cma_area)
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  279  		cma = dev->cma_area;
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  280  	else if ((nid != NUMA_NO_NODE) && dma_contiguous_pernuma_area[nid]
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  281  		&& !(gfp & (GFP_DMA | GFP_DMA32))
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  282  		&& (count > 1)) {
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25 @283  		cma = dma_contiguous_pernuma_area[nid];
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  284  		alloc_from_pernuma = true;
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  285  	} else if (count > 1)
bd2e75633c8012 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  286  		cma = dma_contiguous_default_area;
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  287  
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  288  	/* CMA can be used only in the context which permits sleeping */
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  289  	if (cma && gfpflags_allow_blocking(gfp)) {
90ae409f9eb3bc kernel/dma/contiguous.c       Christoph Hellwig 2019-08-20  290  		size_t align = get_order(size);
c6622a425acd1d kernel/dma/contiguous.c       Nicolin Chen      2019-07-26  291  		size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
c6622a425acd1d kernel/dma/contiguous.c       Nicolin Chen      2019-07-26  292  
c6622a425acd1d kernel/dma/contiguous.c       Nicolin Chen      2019-07-26  293  		page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  294  
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  295  		/* fall back to default cma if failed in per-numa cma */
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  296  		if (!page && alloc_from_pernuma)
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  297  			page = cma_alloc(dma_contiguous_default_area, count,
d6930169a33644 kernel/dma/contiguous.c       Barry Song        2020-06-25  298  				cma_align, gfp & __GFP_NOWARN);
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  299  	}
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  300  
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  301  	return page;
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  302  }
b1d2dc009dece4 kernel/dma/contiguous.c       Nicolin Chen      2019-05-23  303  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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