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642c66d84c
By this point can_vma_merge_right() must have returned true, which implies
can_vma_merge_before() also returned true, which already asserts that the
pgoff is as expected for a merge with the following VMA, thus this
assignment is redundant.
Below is a more detail explanation.
Current definition of can_vma_merge_right() is:
static bool can_vma_merge_right(struct vma_merge_struct *vmg,
bool can_merge_left)
{
if (!vmg->next || vmg->end != vmg->next->vm_start ||
!can_vma_merge_before(vmg))
return false;
...
}
And:
static bool can_vma_merge_before(struct vma_merge_struct *vmg)
{
pgoff_t pglen = PHYS_PFN(vmg->end - vmg->start);
...
if (vmg->next->vm_pgoff == vmg->pgoff + pglen)
return true;
...
}
Which implies vmg->pgoff == vmg->next->vm_pgoff - pglen.
None of these values are changed between the check and prior assignment,
so this was an entirely redundant assignment.
[akpm@linux-foundation.org: remove now-unused local]
[lorenzo.stoakes@oracle.com: rephrase the changelog]
Link: https://lkml.kernel.org/r/20241024093347.18057-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jann Horn <jannh@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.