From: Vlastimil Babka <vbabka@suse.cz>
To: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
kernel-team@android.com, vinmenon@codeaurora.org,
Kees Cook <keescook@chromium.org>,
Matthew Garrett <mjg59@google.com>, Roman Gushchin <guro@fb.com>,
Vlastimil Babka <vbabka@suse.cz>, Jann Horn <jannh@google.com>,
Vijayanand Jitta <vjitta@codeaurora.org>
Subject: [PATCH 5/9] mm, slub: make reclaim_account attribute read-only
Date: Wed, 10 Jun 2020 18:31:31 +0200 [thread overview]
Message-ID: <20200610163135.17364-6-vbabka@suse.cz> (raw)
In-Reply-To: <20200610163135.17364-1-vbabka@suse.cz>
The attribute reflects the SLAB_RECLAIM_ACCOUNT cache flag. It's not clear why
this attribute was writable in the first place, as it's tied to how the cache
is used by its creator, it's not a user tunable. Furthermore:
- it affects slab merging, but that's not being checked while toggled
- if affects whether __GFP_RECLAIMABLE flag is used to allocate page, but
the runtime toggle doesn't update allocflags
- it affects cache_vmstat_idx() so runtime toggling might lead to incosistency
of NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE
Thus make it read-only.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Roman Gushchin <guro@fb.com>
---
mm/slub.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c
index 0108829838e7..8dd2925448ae 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5223,16 +5223,7 @@ static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
{
return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT));
}
-
-static ssize_t reclaim_account_store(struct kmem_cache *s,
- const char *buf, size_t length)
-{
- s->flags &= ~SLAB_RECLAIM_ACCOUNT;
- if (buf[0] == '1')
- s->flags |= SLAB_RECLAIM_ACCOUNT;
- return length;
-}
-SLAB_ATTR(reclaim_account);
+SLAB_ATTR_RO(reclaim_account);
static ssize_t hwcache_align_show(struct kmem_cache *s, char *buf)
{
--
2.26.2
next prev parent reply other threads:[~2020-06-10 16:32 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-10 16:31 [PATCH 0/9] slub_debug fixes and improvements Vlastimil Babka
2020-06-10 16:31 ` [PATCH 1/9] mm, slub: extend slub_debug syntax for multiple blocks Vlastimil Babka
2020-06-10 16:31 ` [PATCH 2/9] mm, slub: make some slub_debug related attributes read-only Vlastimil Babka
2020-06-10 16:31 ` [PATCH 3/9] mm, slub: remove runtime allocation order changes Vlastimil Babka
2020-06-10 16:31 ` [PATCH 4/9] mm, slub: make remaining slub_debug related attributes read-only Vlastimil Babka
2020-06-10 16:31 ` Vlastimil Babka [this message]
2020-06-10 16:31 ` [PATCH 6/9] mm, slub: introduce static key for slub_debug() Vlastimil Babka
2020-06-10 21:59 ` Roman Gushchin
2020-06-17 17:54 ` Kees Cook
2020-06-10 16:31 ` [PATCH 7/9] mm, slub: introduce kmem_cache_debug_flags() Vlastimil Babka
2020-06-10 22:06 ` Roman Gushchin
2020-06-17 17:56 ` Kees Cook
2020-06-18 8:32 ` Vlastimil Babka
2020-06-18 8:37 ` Vlastimil Babka
2020-06-18 19:54 ` Roman Gushchin
2020-06-18 19:56 ` Kees Cook
2020-06-10 16:31 ` [PATCH 8/9] mm, slub: extend checks guarded by slub_debug static key Vlastimil Babka
2020-06-10 22:09 ` Roman Gushchin
2020-06-10 16:31 ` [PATCH 9/9] mm, slab/slub: move and improve cache_from_obj() Vlastimil Babka
2020-06-10 22:46 ` Roman Gushchin
2020-06-11 9:56 ` Vlastimil Babka
2020-06-11 20:04 ` Roman Gushchin
2020-06-17 17:49 ` Kees Cook
2020-06-18 10:10 ` Vlastimil Babka
2020-06-18 19:59 ` Kees Cook
2020-06-18 20:05 ` Roman Gushchin
2020-06-19 19:02 ` Kees Cook
2020-06-24 7:57 ` Vlastimil Babka
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