From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sg-1-104.ptr.blmpb.com (sg-1-104.ptr.blmpb.com [118.26.132.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7E4E8287507 for ; Tue, 3 Feb 2026 08:18:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=118.26.132.104 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770106698; cv=none; b=b6ZSL32lCckhtFRnVYXqYBn3ylgJ19DF2U5HbwtVFt6xpNvCWN9gZBveWoNNDWzUOBcPjCTMxscPVGHJaR/VlLWBTJoqQ5kNEvhrEqSI0Owv21SVIyGSL4RloHmuLQ6PyMpKJuQxIv44wODL0z1NyJijsld/CTe4qhfUHy5qmww= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770106698; c=relaxed/simple; bh=FbP5kJ6ruz8brWh3Iy/A95jlHR9PFvhkVoecrjqIBiw=; h=Message-Id:Cc:From:In-Reply-To:References:Date:Mime-Version: Content-Type:To:Subject; b=CCBb4W5YInErwBDJ8aSwOzesTGC9x/tSOGAn1u5U4VP6ZNFEIWAnQxzyekixEEg7erj4SYe6K45qu21X5O1KjEKqAM2ZbqcEbxIXfiAz/r+RjB9teweOt0cqC4CUX5kJUtRwSgIvOIkGwiOvmlo0Em1GmNU9MHoiwFiRhuljTWw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com; spf=pass smtp.mailfrom=bytedance.com; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b=ppteeARE; arc=none smtp.client-ip=118.26.132.104 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=bytedance.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bytedance.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bytedance.com header.i=@bytedance.com header.b="ppteeARE" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=2212171451; d=bytedance.com; t=1770106680; h=from:subject: mime-version:from:date:message-id:subject:to:cc:reply-to:content-type: mime-version:in-reply-to:message-id; bh=Ro+94Aa/uxuiumnNVETAoZZO1z2xqW2bzXYXE12GuYc=; b=ppteeARESmgocBniDzvZbTwAHoalFcsxXBjYBHExTDuo6WVq3azMcGj7QYE3zqFfv1QE3h wyJBaT9hHHVzBpx4LWDu52PwcDZ3Hoa3/8hISn+kMZS4/7Y3LHVpK16Wxm6fHevQ/eiQpU FSmEqFccAs6a6qBpAXU8mzUV+RxqKiKGV83PxGOZkQ7Ex6UhXTTfd0/Na/kCXHHoGQirl+ /hOvMwvRuMVBnahEeO/4ePi0SDVipm6V4eo4dDjD5Y+ZO1gSyo5LOH1qdwJvV+uesqfI1G dDQko8OAy6KnnNc1QqsrjA4JBxoLOaxRP4n2nE6FCcF0ATqjO+Est0g+fhhRzg== Message-Id: <3e59ca4e-2301-48a7-bb8e-d028f07b1446@bytedance.com> Cc: , , , From: "Qi Zheng" User-Agent: Mozilla Thunderbird In-Reply-To: <20260203073757.135088-1-ahacigu.linux@gmail.com> References: <20260203073757.135088-1-ahacigu.linux@gmail.com> Date: Tue, 3 Feb 2026 16:17:44 +0800 X-Original-From: Qi Zheng Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Lms-Return-Path: Content-Transfer-Encoding: 7bit To: "Altan Hacigumus" , , Subject: Re: [PATCH] mm/shrinker: Fix refcount leak in shrink_slab_memcg() On 2/3/26 3:37 PM, Altan Hacigumus wrote: > When kmem is disabled for memcg, slab-backed shrinkers are skipped. > However, shrink_slab_memcg() doesn't drop the reference acquired via > shrinker_try_get() before continuing. Good catch! > > Add the missing shrinker_put(). > > Fixes: 50d09da8e119 ("mm: shrinker: make memcg slab shrink lockless") > > Signed-off-by: Altan Hacigumus > --- > mm/shrinker.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/mm/shrinker.c b/mm/shrinker.c > index 4a93fd433689..d0be120488b4 100644 > --- a/mm/shrinker.c > +++ b/mm/shrinker.c > @@ -544,8 +544,10 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid, > > /* Call non-slab shrinkers even though kmem is disabled */ > if (!memcg_kmem_online() && > - !(shrinker->flags & SHRINKER_NONSLAB)) > + !(shrinker->flags & SHRINKER_NONSLAB)) { Since memcg_kmem_online() and shrinker->flags cannot be changed dynamically, it's best to remove this shrinker from the bitmap: clear_bit(offset, unit->map); Otherwise LGTM. Acked-by: Qi Zheng Thanks! > + shrinker_put(shrinker); > continue; > + } > > ret = do_shrink_slab(&sc, shrinker, priority); > if (ret == SHRINK_EMPTY) {