On Tue, Oct 13, 2020 at 08:21:13AM -0700, Randy Dunlap wrote: > On 10/13/20 8:12 AM, Mike Rapoport wrote: > > On Tue, Oct 13, 2020 at 07:43:59AM -0700, Randy Dunlap wrote: > >> On 10/13/20 1:09 AM, Mike Rapoport wrote: > >>> On Mon, Oct 12, 2020 at 05:53:01PM +0800, Muchun Song wrote: > >>>> On Mon, Oct 12, 2020 at 5:24 PM Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote: > >>>>> > >>>>> On 10/12/20 10:39 AM, Muchun Song wrote: > >>>>>> On Mon, Oct 12, 2020 at 3:42 PM Eric Dumazet <edumazet@xxxxxxxxxx> wrote: > >>>> > >>>> We are not complaining about TCP using too much memory, but how do > >>>> we know that TCP uses a lot of memory. When I firstly face this problem, > >>>> I do not know who uses the 25GB memory and it is not shown in the /proc/meminfo. > >>>> If we can know the amount memory of the socket buffer via /proc/meminfo, we > >>>> may not need to spend a lot of time troubleshooting this problem. Not everyone > >>>> knows that a lot of memory may be used here. But I believe many people > >>>> should know /proc/meminfo to confirm memory users. > >>> > >>> If I undestand correctly, the problem you are trying to solve is to > >>> simplify troubleshooting of memory usage for people who may not be aware > >>> that networking stack can be a large memory consumer. > >>> > >>> For that a paragraph in 'man 5 proc' maybe a good start: > >>> > >>> >From ddbcf38576d1a2b0e36fe25a27350d566759b664 Mon Sep 17 00:00:00 2001 > >>> From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > >>> Date: Tue, 13 Oct 2020 11:07:35 +0300 > >>> Subject: [PATCH] proc.5: meminfo: add not anout network stack memory > >>> consumption > >>> > >>> Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > >>> --- > >>> man5/proc.5 | 8 ++++++++ > >>> 1 file changed, 8 insertions(+) > >>> > >>> diff --git a/man5/proc.5 b/man5/proc.5 > >>> index ed309380b..8414676f1 100644 > >>> --- a/man5/proc.5 > >>> +++ b/man5/proc.5 > >>> @@ -3478,6 +3478,14 @@ Except as noted below, > >>> all of the fields have been present since at least Linux 2.6.0. > >>> Some fields are displayed only if the kernel was configured > >>> with various options; those dependencies are noted in the list. > >>> +.IP > >>> +Note that significant part of memory allocated by the network stack > >>> +is not accounted in the file. > >>> +The memory consumption of the network stack can be queried > >>> +using > >>> +.IR /proc/net/sockstat > >>> +or > >>> +.BR ss (8) > >>> .RS > >>> .TP > >>> .IR MemTotal " %lu" > >> > >> Hi Mike, > >> > >> Could you tell us what units those values are in? > >> or is that already explained somewhere else? > > > > It is described a few lines above and anyway, "MemTotal" is a part of > > the diff context ;-) > > with no units AFAICT. > > But I was unclear. I wasn't referring to /proc/meminfo, but instead > to /proc/net/sockstat and its units: > > sockets: used 1224 > TCP: inuse 11 orphan 1 tw 1 alloc 26 mem 3 > UDP: inuse 4 mem 2 > UDPLITE: inuse 0 > RAW: inuse 0 > FRAG: inuse 0 memory 0 > > E.g., for TCP and UDP, are those socket counts or some unit of memory? > If units of memory, what unit size? Ah, these are in 4k pages, AFAIU. And, as it seems /proc/net/sockstat lacks a description in proc.5 at all... > thanks. > -- > ~Randy > > -- Sincerely yours, Mike.
