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From: Alexei Starovoitov <alexei.starovoitov@gmail.com>
To: bpf@vger.kernel.org
Cc: daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org,
	vbabka@suse.cz, linux-mm@kvack.org, kernel-team@fb.com
Subject: [PATCH bpf-next] mm: Fix the flipped condition in gfpflags_allow_spinning()
Date: Mon, 10 Mar 2025 13:40:17 +0100	[thread overview]
Message-ID: <20250310124017.187-1-alexei.starovoitov@gmail.com> (raw)

From: Vlastimil Babka <vbabka@suse.cz>

The function gfpflags_allow_spinning() has a bug that makes it return
the opposite result than intended. This could contribute to deadlocks as
usage profilerates, for now it was noticed as a performance regression
due to try_charge_memcg() not refilling memcg stock when it could. Fix
the flipped condition.

Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202503101254.cfd454df-lkp@intel.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 include/linux/gfp.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index ceb226c2e25c..c9fa6309c903 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -55,7 +55,7 @@ static inline bool gfpflags_allow_spinning(const gfp_t gfp_flags)
 	 * regular page allocator doesn't fully support this
 	 * allocation mode.
 	 */
-	return !(gfp_flags & __GFP_RECLAIM);
+	return !!(gfp_flags & __GFP_RECLAIM);
 }
 
 #ifdef CONFIG_HIGHMEM
-- 
2.43.5



             reply	other threads:[~2025-03-10 12:40 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-03-10 12:40 Alexei Starovoitov [this message]
2025-03-10 22:30 ` patchwork-bot+netdevbpf

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