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authorChristoph Hellwig <hch@lst.de>2022-01-21 22:14:44 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-22 08:33:38 +0200
commit0b364446d734da76e421dbfb09e5268270cefaf0 (patch)
tree4e17dbdf0a89028d448625060c273f1eae042003 /mm
parent71024cb4a0bfe7767aec7a128d0a1a13a37b7fcd (diff)
frontswap: remove frontswap_shrink
frontswap_shrink is never called, so remove it. Link: https://lkml.kernel.org/r/20211224062246.1258487-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Juergen Gross <jgross@suse.com> Cc: Dan Streetman <ddstreet@ieee.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Hugh Dickins <hughd@google.com> Cc: Konrad Rzeszutek Wilk <Konrad.wilk@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Vitaly Wool <vitaly.wool@konsulko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/frontswap.c83
1 files changed, 0 insertions, 83 deletions
diff --git a/mm/frontswap.c b/mm/frontswap.c
index dba7f087ee86..a77ebba6101b 100644
--- a/mm/frontswap.c
+++ b/mm/frontswap.c
@@ -341,89 +341,6 @@ static unsigned long __frontswap_curr_pages(void)
return totalpages;
}
-static int __frontswap_unuse_pages(unsigned long total, unsigned long *unused,
- int *swapid)
-{
- int ret = -EINVAL;
- struct swap_info_struct *si = NULL;
- int si_frontswap_pages;
- unsigned long total_pages_to_unuse = total;
- unsigned long pages = 0, pages_to_unuse = 0;
-
- assert_spin_locked(&swap_lock);
- plist_for_each_entry(si, &swap_active_head, list) {
- si_frontswap_pages = atomic_read(&si->frontswap_pages);
- if (total_pages_to_unuse < si_frontswap_pages) {
- pages = pages_to_unuse = total_pages_to_unuse;
- } else {
- pages = si_frontswap_pages;
- pages_to_unuse = 0; /* unuse all */
- }
- /* ensure there is enough RAM to fetch pages from frontswap */
- if (security_vm_enough_memory_mm(current->mm, pages)) {
- ret = -ENOMEM;
- continue;
- }
- vm_unacct_memory(pages);
- *unused = pages_to_unuse;
- *swapid = si->type;
- ret = 0;
- break;
- }
-
- return ret;
-}
-
-/*
- * Used to check if it's necessary and feasible to unuse pages.
- * Return 1 when nothing to do, 0 when need to shrink pages,
- * error code when there is an error.
- */
-static int __frontswap_shrink(unsigned long target_pages,
- unsigned long *pages_to_unuse,
- int *type)
-{
- unsigned long total_pages = 0, total_pages_to_unuse;
-
- assert_spin_locked(&swap_lock);
-
- total_pages = __frontswap_curr_pages();
- if (total_pages <= target_pages) {
- /* Nothing to do */
- *pages_to_unuse = 0;
- return 1;
- }
- total_pages_to_unuse = total_pages - target_pages;
- return __frontswap_unuse_pages(total_pages_to_unuse, pages_to_unuse, type);
-}
-
-/*
- * Frontswap, like a true swap device, may unnecessarily retain pages
- * under certain circumstances; "shrink" frontswap is essentially a
- * "partial swapoff" and works by calling try_to_unuse to attempt to
- * unuse enough frontswap pages to attempt to -- subject to memory
- * constraints -- reduce the number of pages in frontswap to the
- * number given in the parameter target_pages.
- */
-void frontswap_shrink(unsigned long target_pages)
-{
- unsigned long pages_to_unuse = 0;
- int type, ret;
-
- /*
- * we don't want to hold swap_lock while doing a very
- * lengthy try_to_unuse, but swap_list may change
- * so restart scan from swap_active_head each time
- */
- spin_lock(&swap_lock);
- ret = __frontswap_shrink(target_pages, &pages_to_unuse, &type);
- spin_unlock(&swap_lock);
- if (ret == 0)
- try_to_unuse(type, true, pages_to_unuse);
- return;
-}
-EXPORT_SYMBOL(frontswap_shrink);
-
/*
* Count and return the number of frontswap pages across all
* swap devices. This is exported so that backend drivers can