The patch titled
Subject: mm: update the documentation for vfree
has been added to the -mm tree. Its filename is
mm-update-the-documentation-for-vfree.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-update-the-documentation-for-vfree.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-update-the-documentation-for-vfree.patch
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: update the documentation for vfree
Patch series "remove alloc_vm_area", v4.
This series removes alloc_vm_area, which was left over from the big
vmalloc interface rework. It is a rather arkane interface, basicaly the
equivalent of get_vm_area + actually faulting in all PTEs in the allocated
area. It was originally addeds for Xen (which isn't modular to start
with), and then grew users in zsmalloc and i915 which seems to mostly
qualify as abuses of the interface, especially for i915 as a random driver
should not set up PTE bits directly.
This patch (of 11):
* Document that you can call vfree() on an address returned from vmap()
* Remove the note about the minimum size -- the minimum size of a vmalloc
allocation is one page
* Add a Context: section
* Fix capitalisation
* Reword the prohibition on calling from NMI context to avoid a double
negative
Link: https://lkml.kernel.org/r/20201002122204.1534411-1-hch@xxxxxx
Link: https://lkml.kernel.org/r/20201002122204.1534411-2-hch@xxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Cc: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
--- a/mm/vmalloc.c~mm-update-the-documentation-for-vfree
+++ a/mm/vmalloc.c
@@ -2321,20 +2321,21 @@ static void __vfree(const void *addr)
}
/**
- * vfree - release memory allocated by vmalloc()
- * @addr: memory base address
+ * vfree - Release memory allocated by vmalloc()
+ * @addr: Memory base address
*
- * Free the virtually continuous memory area starting at @addr, as
- * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
- * NULL, no operation is performed.
+ * Free the virtually continuous memory area starting at @addr, as obtained
+ * from one of the vmalloc() family of APIs. This will usually also free the
+ * physical memory underlying the virtual allocation, but that memory is
+ * reference counted, so it will not be freed until the last user goes away.
*
- * Must not be called in NMI context (strictly speaking, only if we don't
- * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
- * conventions for vfree() arch-depenedent would be a really bad idea)
+ * If @addr is NULL, no operation is performed.
*
+ * Context:
* May sleep if called *not* from interrupt context.
- *
- * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
+ * Must not be called in NMI context (strictly speaking, it could be
+ * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-depenedent would be a really bad idea).
*/
void vfree(const void *addr)
{
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-debug-do-not-dereference-i_ino-blindly.patch
mm-factor-find_get_incore_page-out-of-mincore_page.patch
mm-use-find_get_incore_page-in-memcontrol.patch
mm-optimise-madvise-willneed.patch
mm-optimise-madvise-willneed-fix.patch
proc-optimise-smaps-for-shmem-entries.patch
i915-use-find_lock_page-instead-of-find_lock_entry.patch
mm-convert-find_get_entry-to-return-the-head-page.patch
mm-convert-find_get_entry-to-return-the-head-page-fix.patch
mm-shmem-return-head-page-from-find_lock_entry.patch
mm-shmem-return-head-page-from-find_lock_entry-fix.patch
mm-add-find_lock_head.patch
mm-filemap-fix-filemap_map_pages-for-thp.patch
mm-account-pmd-tables-like-pte-tables.patch
mm-move-pagedoublemap-bit.patch
mm-simplify-pagedoublemap-with-pf_second-policy.patch
page_alloc-fix-freeing-non-compound-pages.patch
xarray-add-xa_get_order.patch
xarray-add-xas_split.patch
xarray-add-xas_split-fix-2.patch
mm-filemap-fix-storing-to-a-thp-shadow-entry.patch
mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch
mm-memory-remove-page-fault-assumption-of-compound-page-size.patch
mm-page_owner-change-split_page_owner-to-take-a-count.patch
mm-huge_memory-fix-page_trans_huge_mapcount-assumption-of-thp-size.patch
mm-huge_memory-fix-can_split_huge_page-assumption-of-thp-size.patch
mm-rmap-fix-assumptions-of-thp-size.patch
mm-truncate-fix-truncation-for-pages-of-arbitrary-size.patch
mm-page-writeback-support-tail-pages-in-wait_for_stable_page.patch
mm-vmscan-allow-arbitrary-sized-pages-to-be-paged-out.patch
fs-add-a-filesystem-flag-for-thps.patch
fs-do-not-update-nr_thps-for-mappings-which-support-thps.patch
mm-readahead-add-define_readahead.patch
mm-readahead-make-page_cache_ra_unbounded-take-a-readahead_control.patch
mm-readahead-make-do_page_cache_ra-take-a-readahead_control.patch
mm-readahead-add-page_cache_sync_ra-and-page_cache_async_ra.patch
ramfs-fix-nommu-mmap-with-gaps-in-the-page-cache.patch
harden-autofs-ioctl-table.patch
mm-update-the-documentation-for-vfree.patch
