From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: [PATCH v7 10/10] memcg: enable accounting for ldt_struct objects Date: Tue, 27 Jul 2021 08:34:23 +0300 Message-ID: <38010594-50fe-c06d-7cb0-d1f77ca422f3@virtuozzo.com> References: <6f21a0e0-bd36-b6be-1ffa-0dc86c06c470@virtuozzo.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=QOm/SWMV/Asmk/Sj3wEkt1IsJkdhz+j421ZJ6yW2Ajw=; b=vhl1qmBiYUKwAvV9lqD QMCbVBT3bPeLgAL4tCas91WdXWvkx8RMGHbZGanOuOoWB/DMRrRYbWwE21/q7zDJWrSM7vkgzXmSg wLCaGgc1EwknLaQ4Aj+gMMQusELjTBdTXq1iOedLAbvyJt9TxSEm6VtWckDYHy7CqsJEh70TSBo=; In-Reply-To: Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii" To: Andrew Morton Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , Shakeel Butt , Johannes Weiner , Vladimir Davydov , Roman Gushchin , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Each task can request own LDT and force the kernel to allocate up to 64Kb memory per-mm. There are legitimate workloads with hundreds of processes and there can be hundreds of workloads running on large machines. The unaccounted memory can cause isolation issues between the workloads particularly on highly utilized machines. It makes sense to account for this objects to restrict the host's memory consumption from inside the memcg-limited container. Signed-off-by: Vasily Averin Acked-by: Borislav Petkov --- arch/x86/kernel/ldt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/ldt.c b/arch/x86/kernel/ldt.c index aa15132..525876e 100644 --- a/arch/x86/kernel/ldt.c +++ b/arch/x86/kernel/ldt.c @@ -154,7 +154,7 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) if (num_entries > LDT_ENTRIES) return NULL; - new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL); + new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL_ACCOUNT); if (!new_ldt) return NULL; @@ -168,9 +168,9 @@ static struct ldt_struct *alloc_ldt_struct(unsigned int num_entries) * than PAGE_SIZE. */ if (alloc_size > PAGE_SIZE) - new_ldt->entries = vzalloc(alloc_size); + new_ldt->entries = __vmalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO); else - new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL); + new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT); if (!new_ldt->entries) { kfree(new_ldt); -- 1.8.3.1