mm/vmalloc: add adjust_search_size parameter

mm/vmalloc: add adjust_search_size parameter

Extend the find_vmap_lowest_match() function with one more parameter.  It
is "adjust_search_size" boolean variable, so it is possible to control an
accuracy of search block if a specific alignment is required.

With this patch, a search size is always adjusted, to serve a request as
fast as possible because of performance reason.

But there is one exception though, it is short ranges where requested size
corresponds to passed vstart/vend restriction together with a specific
alignment request.  In such scenario an adjustment wold not lead to
success allocation.

Link: https://lkml.kernel.org/r/20220119143540.601149-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki <uladzislau.rezki@sony.com>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>