From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanpeng Li Subject: Re: [PATCH 1/5 v2] memcg: replace unsigned long by u64 to avoid overflow Date: Wed, 4 Jul 2012 20:24:27 +0800 Message-ID: <20120704122427.GA21598@kernel> References: <1340604266-7937-1-git-send-email-liwp.linux@gmail.com> <20120625075215.GW27816@cmpxchg.org> <4FE82193.1070307@jp.fujitsu.com> Reply-To: Wanpeng Li Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=M6mFQ0qj2VI2YUwo1Yq9K2XLI6lJ43B65Xlg1vqjU1c=; b=owWn/QZEmfQjBmo+IDooOZY0rO9PApqJPlctzaf/D2zSKMs98zE2TfFXCbyruk9+67 tERnpFvoFWV49NRv+QgiNpRmHjnGmS0Z09slGTVM6WTW9YGQWfQJd3L5VDvU6MWUamH6 oXCuD+wo9LFP63DsJT5b7/jo44r1y8ARuKjnxd1ap7PZAenPotOrk8rIqmXgtXnbFeTR J28cHjuKA7udrLV2C/flfPzCCbpfHjPh+GnK5o5T9Tl6Dv8x/tvjEgzsCeT4HsYAwuLx aPLlJO3QmwxrINon34N/jfvWvUgWRpKY7jI/IXWcDKdvmjTz3vgHQR75NZmvb26iDQdQ cIOQ== Content-Disposition: inline In-Reply-To: <4FE82193.1070307-+CUm20s59erQFUHtdCDX3A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Johannes Weiner Cc: Michal Hocko , Balbir Singh , AndrewMorton , Eric Dumazet , Mike Frysinger , Arun Sharma , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wanpeng Li On Mon, Jun 25, 2012 at 05:30:11PM +0900, Kamezawa Hiroyuki wrote: >(2012/06/25 16:52), Johannes Weiner wrote: >>On Mon, Jun 25, 2012 at 02:04:20PM +0800, Wanpeng Li wrote: >>>Changlog: >>> >>>V2 -> V1: >>>* fix zone_page_state()::/include/linux/vmstat.h returns 'unsigned long' >>> >>>From: Wanpeng Li >>> >>>Since the return value variable in mem_cgroup_zone_nr_lru_pages and >>>mem_cgroup_node_nr_lru_pages functions are u64, so replace the return >>>value of funtions by u64 to avoid overflow. >>> >>>Signed-off-by: Wanpeng Li >>>--- >>> include/linux/vmstat.h | 2 +- >>> mm/memcontrol.c | 5 ++--- >>> 2 files changed, 3 insertions(+), 4 deletions(-) >>> >>>diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h >>>index 65efb92..6a14291 100644 >>>--- a/include/linux/vmstat.h >>>+++ b/include/linux/vmstat.h >>>@@ -106,7 +106,7 @@ static inline unsigned long global_page_state(enum zone_stat_item item) >>> return x; >>> } >>> >>>-static inline unsigned long zone_page_state(struct zone *zone, >>>+static inline u64 zone_page_state(struct zone *zone, >>> enum zone_stat_item item) >>> { >>> long x = atomic_long_read(&zone->vm_stat[item]); >> >>We established that there is no known reason to use ulong for page >>counters and that IF YOU HAD ONE, you should obviously say so and then >>do a wholesale conversion. But I don't think you have one. >> >>This patch makes absolutely no sense. >> >I agree. Then, Nack from me. > >Thanks, >-Kame static unsigned long mem_cgroup_node_nr_lru_pages(struct mem_cgroup *memcg, int nid, unsigned int lru_mask) { u64 total = 0; int zid; for (zid = 0; zid < MAX_NR_ZONES; zid++) total += mem_cgroup_zone_nr_lru_pages(memcg, nid, zid, lru_mask); return total; } Since you use unsigned long to caculate nr_pages and unsigned long long to caculate bytes, so u64 in function mem_cgroup_node_nr_lru_pages should replace by unsigned long to save kernel stack, right? Regards, Wanpeng Li > >