From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5EEF42C21F7; Tue, 12 Aug 2025 19:28:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755026892; cv=none; b=jYgzGQOXX/s8rSgkR2jmy+396wj6nNE7MyCeKc1JDF6VhjOMecbL6+bfqhyKS9UEraAemhUORgANMUJ4xjJm9fg7iVbca/kJUDFhF+izfQVttsVEE5F5EHroHVfQYH6n4g2TkedCcmO5zWOk0FciAdfhErPdQo9NIRQ6mdiLGKY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755026892; c=relaxed/simple; bh=sZ1MvrfYTiXMWEk+jqegw5/6bO1O66mb21o9fFr/I7o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gnfiD5Qu1SeejU1792d+/yfzneVmYqI/7rnHumB2UjD1XZdC5f039+1DyCoZEblDiCeR0X/mwKOgHNchM4omcub2O5exGyOqMlroklA3w2HytBlSYgLXNPB7i+216nPkvFfR68bTy4YUK8IgRnq+f8aO7OEL+ffHp7y/YGXb7iU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=H2ut/tLH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="H2ut/tLH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3860C4CEF0; Tue, 12 Aug 2025 19:28:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755026892; bh=sZ1MvrfYTiXMWEk+jqegw5/6bO1O66mb21o9fFr/I7o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H2ut/tLHcnGDxRXCMQr2rlzwv1bLr4t7zB+CD6+kKZwjEHOxJl+lY4tPMmT9Ymkla Gh5hikM2s6VmKOPPAzLA2gV4NMh/XMKZa+rD3HyQnRELaNbAVbx7DRMfOmb0IYDRUR RJWAgYjSnUc+m92eXSJaN76x7nQcyok6XB/vcU68= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kemeng Shi , Kairui Song , Baoquan He , Johannes Weiner , Andrew Morton Subject: [PATCH 6.15 470/480] mm: swap: move nr_swap_pages counter decrement from folio_alloc_swap() to swap_range_alloc() Date: Tue, 12 Aug 2025 19:51:18 +0200 Message-ID: <20250812174416.767692496@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812174357.281828096@linuxfoundation.org> References: <20250812174357.281828096@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kemeng Shi commit 4f78252da887ee7e9d1875dd6e07d9baa936c04f upstream. Patch series "Some randome fixes and cleanups to swapfile". Patch 0-3 are some random fixes. Patch 4 is a cleanup. More details can be found in respective patches. This patch (of 4): When folio_alloc_swap() encounters a failure in either mem_cgroup_try_charge_swap() or add_to_swap_cache(), nr_swap_pages counter is not decremented for allocated entry. However, the following put_swap_folio() will increase nr_swap_pages counter unpairly and lead to an imbalance. Move nr_swap_pages decrement from folio_alloc_swap() to swap_range_alloc() to pair the nr_swap_pages counting. Link: https://lkml.kernel.org/r/20250522122554.12209-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20250522122554.12209-2-shikemeng@huaweicloud.com Fixes: 0ff67f990bd4 ("mm, swap: remove swap slot cache") Signed-off-by: Kemeng Shi Reviewed-by: Kairui Song Reviewed-by: Baoquan He Cc: Johannes Weiner Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/swapfile.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -1115,6 +1115,7 @@ static void swap_range_alloc(struct swap if (vm_swap_full()) schedule_work(&si->reclaim_work); } + atomic_long_sub(nr_entries, &nr_swap_pages); } static void swap_range_free(struct swap_info_struct *si, unsigned long offset, @@ -1313,7 +1314,6 @@ int folio_alloc_swap(struct folio *folio if (add_to_swap_cache(folio, entry, gfp | __GFP_NOMEMALLOC, NULL)) goto out_free; - atomic_long_sub(size, &nr_swap_pages); return 0; out_free: