From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 667D4C77B7F for ; Sat, 13 May 2023 00:27:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240657AbjEMA1Z (ORCPT ); Fri, 12 May 2023 20:27:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240883AbjEMA1Y (ORCPT ); Fri, 12 May 2023 20:27:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C0012686 for ; Fri, 12 May 2023 17:27:22 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A0E3465320 for ; Sat, 13 May 2023 00:27:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F394EC433EF; Sat, 13 May 2023 00:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1683937641; bh=69BpZ7pstEnxVVGkAfYQBz1e1pb1um8KIPZlcAA/PtY=; h=Date:To:From:Subject:From; b=ZaRyue0sHRbtwAGSsNzXLAJVAVxVj4QGZrrfiRJmMaPftjAH8jv8mPmW+LWiIA8fC 6v67DY9bi9H8SfJXm0upYokmUdPFASCw23rZom9+CQdlG3bc316wFDm2AnvJ6H7KpK Fiz+Gye3Nffqjd3vueDwT/K1PfYODTQDPsd7MlZ0= Date: Fri, 12 May 2023 17:27:20 -0700 To: mm-commits@vger.kernel.org, tglx@linutronix.de, luto@kernel.org, bristot@kernel.org, bigeasy@linutronix.de, haifeng.xu@shopee.com, akpm@linux-foundation.org From: Andrew Morton Subject: + fork-optimize-memcg_charge_kernel_stack-a-bit.patch added to mm-nonmm-unstable branch Message-Id: <20230513002720.F394EC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: fork: optimize memcg_charge_kernel_stack() a bit has been added to the -mm mm-nonmm-unstable branch. Its filename is fork-optimize-memcg_charge_kernel_stack-a-bit.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/fork-optimize-memcg_charge_kernel_stack-a-bit.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Haifeng Xu Subject: fork: optimize memcg_charge_kernel_stack() a bit Date: Mon, 8 May 2023 06:44:58 +0000 Since commit f1c1a9ee00e4 ("fork: Move memcg_charge_kernel_stack() into CONFIG_VMAP_STACK"), memcg_charge_kernel_stack() has been moved into CONFIG_VMAP_STACK block, so the CONFIG_VMAP_STACK check can be removed. Furthermore, memcg_charge_kernel_stack() is only invoked by alloc_thread_stack_node() instead of dup_task_struct(). If memcg_kmem_charge_page() fails, the uncharge process is handled in memcg_charge_kernel_stack() itself instead of free_thread_stack(), so remove the incorrect comments. If memcg_charge_kernel_stack() fails to charge pages used by kernel stack, only charged pages need to be uncharged. It's unnecessary to uncharge those pages which memory cgroup pointer is NULL. Link: https://lkml.kernel.org/r/20230508064458.32855-1-haifeng.xu@shopee.com Signed-off-by: Haifeng Xu Cc: Andy Lutomirski Cc: Daniel Bristot de Oliveira Cc: Sebastian Andrzej Siewior Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- kernel/fork.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) --- a/kernel/fork.c~fork-optimize-memcg_charge_kernel_stack-a-bit +++ a/kernel/fork.c @@ -252,23 +252,20 @@ static int memcg_charge_kernel_stack(str { int i; int ret; + int nr_charged = 0; - BUILD_BUG_ON(IS_ENABLED(CONFIG_VMAP_STACK) && PAGE_SIZE % 1024 != 0); + BUILD_BUG_ON(PAGE_SIZE % 1024 != 0); BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE); for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) { ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0); if (ret) goto err; + nr_charged++; } return 0; err: - /* - * If memcg_kmem_charge_page() fails, page's memory cgroup pointer is - * NULL, and memcg_kmem_uncharge_page() in free_thread_stack() will - * ignore this page. - */ - for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) + for (i = 0; i < nr_charged; i++) memcg_kmem_uncharge_page(vm->pages[i], 0); return ret; } _ Patches currently in -mm which might be from haifeng.xu@shopee.com are memcg-oom-remove-unnecessary-check-in-mem_cgroup_oom_synchronize.patch memcg-oom-remove-explicit-wakeup-in-mem_cgroup_oom_synchronize.patch mm-oom-do-not-check-0-mask-in-out_of_memory.patch fork-optimize-memcg_charge_kernel_stack-a-bit.patch