linux-kernel - [PATCH] mm/z3fold.c: Allow __GFP_HIGHMEM in z3fold

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Date:   Fri, 12 Jul 2019 15:21:18 -0700
From:   Henry Burns <henryburns@...gle.com>
To:     Vitaly Wool <vitalywool@...il.com>,
        Andrew Morton <akpm@...ux-foundation.org>
Cc:     Vitaly Vul <vitaly.vul@...y.com>,
        Shakeel Butt <shakeelb@...gle.com>,
        Jonathan Adams <jwadams@...gle.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Snild Dolkow <snild@...y.com>,
        Thomas Gleixner <tglx@...utronix.de>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, Henry Burns <henryburns@...gle.com>
Subject: [PATCH] mm/z3fold.c: Allow __GFP_HIGHMEM in z3fold_alloc

One of the gfp flags used to show that a page is movable is
__GFP_HIGHMEM.  Currently z3fold_alloc() fails when __GFP_HIGHMEM is
passed.  Now that z3fold pages are movable, we allow __GFP_HIGHMEM. We
strip the movability related flags from the call to kmem_cache_alloc()
for our slots since it is a kernel allocation.

Signed-off-by: Henry Burns <henryburns@...gle.com>
---
 mm/z3fold.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/z3fold.c b/mm/z3fold.c
index e78f95284d7c..cb567ddf051c 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -193,7 +193,8 @@ static inline struct z3fold_buddy_slots *alloc_slots(struct z3fold_pool *pool,
 							gfp_t gfp)
 {
 	struct z3fold_buddy_slots *slots = kmem_cache_alloc(pool->c_handle,
-							    gfp);
+							    (gfp & ~(__GFP_HIGHMEM
+								   | __GFP_MOVABLE)));
 
 	if (slots) {
 		memset(slots->slot, 0, sizeof(slots->slot));
@@ -844,7 +845,7 @@ static int z3fold_alloc(struct z3fold_pool *pool, size_t size, gfp_t gfp,
 	enum buddy bud;
 	bool can_sleep = gfpflags_allow_blocking(gfp);
 
-	if (!size || (gfp & __GFP_HIGHMEM))
+	if (!size)
 		return -EINVAL;
 
 	if (size > PAGE_SIZE)
-- 
2.22.0.510.g264f2c817a-goog