mm, bpf: Use memcg in try_alloc_pages().

JIRA: https://issues.redhat.com/browse/RHEL-78202

commit e8d78db
Author: Alexei Starovoitov <ast@kernel.org>
Date:   Fri Feb 21 18:44:26 2025 -0800

    mm, bpf: Use memcg in try_alloc_pages().

    Unconditionally use __GFP_ACCOUNT in try_alloc_pages().
    The caller is responsible to setup memcg correctly.
    All BPF memory accounting is memcg based.

    Acked-by: Vlastimil Babka <vbabka@suse.cz>
    Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>
    Link: https://lore.kernel.org/r/20250222024427.30294-6-alexei.starovoitov@gmail.com
    Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Signed-off-by: Gregory Bell <grbell@redhat.com>

Author: Gbell26

mm/page_alloc.c

@@ -7176,7 +7176,8 @@ struct page *try_alloc_pages_noprof(int nid, unsigned int order)
 	 * specify it here to highlight that try_alloc_pages()
 	 * doesn't want to deplete reserves.
 	 */
-	gfp_t alloc_gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_NOMEMALLOC;
+	gfp_t alloc_gfp = __GFP_NOWARN | __GFP_ZERO | __GFP_NOMEMALLOC
+			| __GFP_ACCOUNT;
 	unsigned int alloc_flags = ALLOC_TRYLOCK;
 	struct alloc_context ac = { };
 	struct page *page;
@@ -7220,6 +7221,11 @@ struct page *try_alloc_pages_noprof(int nid, unsigned int order)
 
 	/* Unlike regular alloc_pages() there is no __alloc_pages_slowpath(). */
 
+	if (memcg_kmem_online() && page &&
+	    unlikely(__memcg_kmem_charge_page(page, alloc_gfp, order) != 0)) {
+		free_pages_nolock(page, order);
+		page = NULL;
+	}
 	trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype);
 	kmsan_alloc_page(page, order, alloc_gfp);
 	return page;