From mboxrd@z Thu Jan 1 00:00:00 1970 From: Minchan Kim Subject: Re: [PATCH 4/5] mm: zswap: add basic meminfo and vmstat coverage Date: Wed, 27 Apr 2022 13:29:34 -0700 Message-ID: References: <20220427160016.144237-1-hannes@cmpxchg.org> <20220427160016.144237-5-hannes@cmpxchg.org> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=KjZdJc+2UDuaCV9hUSLVuNI4CiOYxCjI+J/98h/W9G4=; b=Tac3djEA5bXqIgvvbxyz8RUsVLAM/lkHxNcYv/gitY3QhUpuLEKTucRMeN/6RsXCGY o+ND4wPwR7gIoVajI8XzV34aqcMZYBllRJa5CVXDwBN9THDIzgLL7016DHdilf1gzjMz JBJSBtSylrg2tT/vIHuAsyDgpuPlKRq43zYsflK5fOqXp1BiJE+1A1+Mu1h/oSLoWtio 2hWay8lfn1y8G5t3h/vJ5ZSoxP6MHkL/FCYcr4gUwQao3/hJOqIu6jF52DW8/vVqxW3u bDaHlEKJ801uxbQhxfssVyszMyKhnTbbk9wfJf/4+AJLMyhhD4fHNXagJ1XlR7rrf97D RTNw== Sender: Minchan Kim Content-Disposition: inline In-Reply-To: <20220427160016.144237-5-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Johannes Weiner Cc: Andrew Morton , Michal Hocko , Roman Gushchin , Shakeel Butt , Seth Jennings , Dan Streetman , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org Hi Johannes, On Wed, Apr 27, 2022 at 12:00:15PM -0400, Johannes Weiner wrote: > Currently it requires poking at debugfs to figure out the size and > population of the zswap cache on a host. There are no counters for > reads and writes against the cache. As a result, it's difficult to > understand zswap behavior on production systems. > > Print zswap memory consumption and how many pages are zswapped out in > /proc/meminfo. Count zswapouts and zswapins in /proc/vmstat. > > Signed-off-by: Johannes Weiner > --- > fs/proc/meminfo.c | 7 +++++++ > include/linux/swap.h | 5 +++++ > include/linux/vm_event_item.h | 4 ++++ > mm/vmstat.c | 4 ++++ > mm/zswap.c | 13 ++++++------- > 5 files changed, 26 insertions(+), 7 deletions(-) > > diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c > index 6fa761c9cc78..6e89f0e2fd20 100644 > --- a/fs/proc/meminfo.c > +++ b/fs/proc/meminfo.c > @@ -86,6 +86,13 @@ static int meminfo_proc_show(struct seq_file *m, void *v) > > show_val_kb(m, "SwapTotal: ", i.totalswap); > show_val_kb(m, "SwapFree: ", i.freeswap); > +#ifdef CONFIG_ZSWAP > + seq_printf(m, "Zswap: %8lu kB\n", > + (unsigned long)(zswap_pool_total_size >> 10)); > + seq_printf(m, "Zswapped: %8lu kB\n", > + (unsigned long)atomic_read(&zswap_stored_pages) << > + (PAGE_SHIFT - 10)); > +#endif I agree it would be very handy to have the memory consumption in meminfo https://lore.kernel.org/all/YYwZXrL3Fu8%2FvLZw-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org/ If we really go this Zswap only metric instead of general term "Compressed", I'd like to post maybe "Zram:" with same reason in this patchset. Do you think that's better idea instead of introducing general term like "Compressed:" or something else?