linux.git/mm, branch v6.4-rc2 Linux kernel source tree Merge tag 'mm-stable-2023-05-06-10-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2023-05-06T18:43:08+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-05-06T18:43:08+00:00 fc4354c6e5c21257cf4a50b32f7c11c7d65c55b3 Pull dmapool updates - again - from Andrew Morton: "Reinstate the dmapool changes which were accidentally removed by a mishap on the last commit in the previous attempt at the series" Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup"). [ The whole old series: def8574308ed..2d55c16c0c54 results in an empty diff because that last commit ended up being just a revert of all that came everything before it. - Linus ] * tag 'mm-stable-2023-05-06-10-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: dmapool: link blocks across pages dmapool: don't memset on free twice dmapool: simplify freeing dmapool: consolidate page initialization dmapool: rearrange page alloc failure handling dmapool: move debug code to own functions dmapool: speedup DMAPOOL_DEBUG with init_on_alloc dmapool: cleanup integer types dmapool: use sysfs_emit() instead of scnprintf() dmapool: remove checks for dev == NULL 
Pull dmapool updates - again - from Andrew Morton:
 "Reinstate the dmapool changes which were accidentally removed by a
  mishap on the last commit in the previous attempt at the series"

Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup").

[ The whole old series: def8574308ed..2d55c16c0c54 results in an empty
  diff because that last commit ended up being just a revert of all that
  came everything before it.     - Linus ]

* tag 'mm-stable-2023-05-06-10-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  dmapool: link blocks across pages
  dmapool: don't memset on free twice
  dmapool: simplify freeing
  dmapool: consolidate page initialization
  dmapool: rearrange page alloc failure handling
  dmapool: move debug code to own functions
  dmapool: speedup DMAPOOL_DEBUG with init_on_alloc
  dmapool: cleanup integer types
  dmapool: use sysfs_emit() instead of scnprintf()
  dmapool: remove checks for dev == NULL
Merge tag 'mm-hotfixes-stable-2023-05-06-10-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2023-05-06T18:25:03+00:00 Linus Torvalds torvalds@linux-foundation.org 2023-05-06T18:25:03+00:00 706ce3caea1cc1dab8c7fd6e7d1389b46ad1570e Pull hotfixes from Andrew Morton: "Five hotfixes. Three are cc:stable, two pertain to merge window changes" * tag 'mm-hotfixes-stable-2023-05-06-10-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: afs: fix the afs_dir_get_folio return value nilfs2: do not write dirty data after degenerating to read-only mm: do not reclaim private data from pinned page nilfs2: fix infinite loop in nilfs_mdt_get_block() mm/mmap/vma_merge: always check invariants 
Pull hotfixes from Andrew Morton:
 "Five hotfixes.

  Three are cc:stable, two pertain to merge window changes"

* tag 'mm-hotfixes-stable-2023-05-06-10-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  afs: fix the afs_dir_get_folio return value
  nilfs2: do not write dirty data after degenerating to read-only
  mm: do not reclaim private data from pinned page
  nilfs2: fix infinite loop in nilfs_mdt_get_block()
  mm/mmap/vma_merge: always check invariants
dmapool: link blocks across pages 2023-05-06T17:33:38+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:24+00:00 da9619a30e73b59605ed998bf7bc4359f5c0029a The allocated dmapool pages are never freed for the lifetime of the pool. There is no need for the two level list+stack lookup for finding a free block since nothing is ever removed from the list. Just use a simple stack, reducing time complexity to constant. The implementation inserts the stack linking elements and the dma handle of the block within itself when freed. This means the smallest possible dmapool block is increased to at most 16 bytes to accommodate these fields, but there are no exisiting users requesting a dma pool smaller than that anyway. Removing the list has a significant change in performance. Using the kernel's micro-benchmarking self test: Before: # modprobe dmapool_test dmapool test: size:16 blocks:8192 time:57282 dmapool test: size:64 blocks:8192 time:172562 dmapool test: size:256 blocks:8192 time:789247 dmapool test: size:1024 blocks:2048 time:371823 dmapool test: size:4096 blocks:1024 time:362237 After: # modprobe dmapool_test dmapool test: size:16 blocks:8192 time:24997 dmapool test: size:64 blocks:8192 time:26584 dmapool test: size:256 blocks:8192 time:33542 dmapool test: size:1024 blocks:2048 time:9022 dmapool test: size:4096 blocks:1024 time:6045 The module test allocates quite a few blocks that may not accurately represent how these pools are used in real life. For a more marco level benchmark, running fio high-depth + high-batched on nvme, this patch shows submission and completion latency reduced by ~100usec each, 1% IOPs improvement, and perf record's time spent in dma_pool_alloc/free were reduced by half. [kbusch@kernel.org: push new blocks in ascending order] Link: https://lkml.kernel.org/r/20230221165400.1595247-1-kbusch@meta.com Link: https://lkml.kernel.org/r/20230126215125.4069751-12-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The allocated dmapool pages are never freed for the lifetime of the pool. 
There is no need for the two level list+stack lookup for finding a free
block since nothing is ever removed from the list.  Just use a simple
stack, reducing time complexity to constant.

The implementation inserts the stack linking elements and the dma handle
of the block within itself when freed.  This means the smallest possible
dmapool block is increased to at most 16 bytes to accommodate these
fields, but there are no exisiting users requesting a dma pool smaller
than that anyway.

Removing the list has a significant change in performance. Using the
kernel's micro-benchmarking self test:

Before:

  # modprobe dmapool_test
  dmapool test: size:16   blocks:8192   time:57282
  dmapool test: size:64   blocks:8192   time:172562
  dmapool test: size:256  blocks:8192   time:789247
  dmapool test: size:1024 blocks:2048   time:371823
  dmapool test: size:4096 blocks:1024   time:362237

After:

  # modprobe dmapool_test
  dmapool test: size:16   blocks:8192   time:24997
  dmapool test: size:64   blocks:8192   time:26584
  dmapool test: size:256  blocks:8192   time:33542
  dmapool test: size:1024 blocks:2048   time:9022
  dmapool test: size:4096 blocks:1024   time:6045

The module test allocates quite a few blocks that may not accurately
represent how these pools are used in real life.  For a more marco level
benchmark, running fio high-depth + high-batched on nvme, this patch shows
submission and completion latency reduced by ~100usec each, 1% IOPs
improvement, and perf record's time spent in dma_pool_alloc/free were
reduced by half.

[kbusch@kernel.org: push new blocks in ascending order]
  Link: https://lkml.kernel.org/r/20230221165400.1595247-1-kbusch@meta.com
Link: https://lkml.kernel.org/r/20230126215125.4069751-12-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: don't memset on free twice 2023-05-06T17:33:38+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:23+00:00 8ecc369554219060367fc589661d2b7ab201e923 If debug is enabled, dmapool will poison the range, so no need to clear it to 0 immediately before writing over it. Link: https://lkml.kernel.org/r/20230126215125.4069751-11-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
If debug is enabled, dmapool will poison the range, so no need to clear it
to 0 immediately before writing over it.

Link: https://lkml.kernel.org/r/20230126215125.4069751-11-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: simplify freeing 2023-05-06T17:33:37+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:22+00:00 cc669954ab38866c1aba73c27e17bb07bcb4a194 The actions for busy and not busy are mostly the same, so combine these and remove the unnecessary function. Also, the pool is about to be freed so there's no need to poison the page data since we only check for poison on alloc, which can't be done on a freed pool. Link: https://lkml.kernel.org/r/20230126215125.4069751-10-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
The actions for busy and not busy are mostly the same, so combine these
and remove the unnecessary function.  Also, the pool is about to be freed
so there's no need to poison the page data since we only check for poison
on alloc, which can't be done on a freed pool.

Link: https://lkml.kernel.org/r/20230126215125.4069751-10-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: consolidate page initialization 2023-05-06T17:33:37+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:21+00:00 f0bccea6bc0caa0db9c68d28123f242a6295c5dd Various fields of the dma pool are set in different places. Move it all to one function. Link: https://lkml.kernel.org/r/20230126215125.4069751-9-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Various fields of the dma pool are set in different places. Move it all
to one function.

Link: https://lkml.kernel.org/r/20230126215125.4069751-9-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: rearrange page alloc failure handling 2023-05-06T17:33:37+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:20+00:00 5407df10e5754b80d43697a75484bacda048fef8 Handle the error in a condition so the good path can be in the normal flow. Link: https://lkml.kernel.org/r/20230126215125.4069751-8-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Handle the error in a condition so the good path can be in the normal
flow.

Link: https://lkml.kernel.org/r/20230126215125.4069751-8-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: move debug code to own functions 2023-05-06T17:33:37+00:00 Keith Busch kbusch@kernel.org 2023-01-26T21:51:19+00:00 d93e08b7556fcd393b7fd1eb421cb44e5fae314c Clean up the normal path by moving the debug code outside it. Link: https://lkml.kernel.org/r/20230126215125.4069751-7-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Clean up the normal path by moving the debug code outside it.

Link: https://lkml.kernel.org/r/20230126215125.4069751-7-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: speedup DMAPOOL_DEBUG with init_on_alloc 2023-05-06T17:33:36+00:00 Tony Battersby tonyb@cybernetics.com 2023-01-26T21:51:18+00:00 290911c56f98ac7af9354108f3d16da5d6c5189c Avoid double-memset of the same allocated memory in dma_pool_alloc() when both DMAPOOL_DEBUG is enabled and init_on_alloc=1. Link: https://lkml.kernel.org/r/20230126215125.4069751-6-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Avoid double-memset of the same allocated memory in dma_pool_alloc() when
both DMAPOOL_DEBUG is enabled and init_on_alloc=1.

Link: https://lkml.kernel.org/r/20230126215125.4069751-6-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
dmapool: cleanup integer types 2023-05-06T17:33:36+00:00 Tony Battersby tonyb@cybernetics.com 2023-01-26T21:51:17+00:00 790233528d338f1467662761cf1e871086483ab8 To represent the size of a single allocation, dmapool currently uses 'unsigned int' in some places and 'size_t' in other places. Standardize on 'unsigned int' to reduce overhead, but use 'size_t' when counting all the blocks in the entire pool. Link: https://lkml.kernel.org/r/20230126215125.4069751-5-kbusch@meta.com Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup") Signed-off-by: Tony Battersby <tonyb@cybernetics.com> Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
To represent the size of a single allocation, dmapool currently uses
'unsigned int' in some places and 'size_t' in other places.  Standardize
on 'unsigned int' to reduce overhead, but use 'size_t' when counting all
the blocks in the entire pool.

Link: https://lkml.kernel.org/r/20230126215125.4069751-5-kbusch@meta.com
Fixes: 2d55c16c0c54 ("dmapool: create/destroy cleanup")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>