On Wed, 13 Feb 2019 09:37:11 +0100 Stefano Brivio <sbri...@redhat.com> wrote:
> On Tue, 12 Feb 2019 16:42:04 -0800 > Eric Dumazet <eric.duma...@gmail.com> wrote: > > > I do not get it. > > > > "ss -emoi " uses almost 1KB per socket. > > > > 10,000,000 sockets -> we need about 10GB of memory ??? > > > > This is a serious regression. > > I guess this is rather subjective: the worst case I considered back then > was the output of 'ss -tei0' (less than 500 bytes) for one million > sockets, which gives 500M of memory, which should in turn be fine on a > machine handling one million sockets. > > Now, if 'ss -emoi' on 10 million sockets is an actual use case (out of > curiosity: how are you going to process that output? Would JSON help?), > I see two easy options to solve this: > > 1. flush the output every time we reach a given buffer size (1M > perhaps). This might make the resulting blocks slightly unaligned, > with occasional loss of readability on lines occurring every 1k to > 10k sockets approximately, even though after 1k sockets column sizes > won't change much (it looks anyway better than the original), and I > don't expect anybody to actually scroll that output > > 2. add a switch for unbuffered output, but then you need to remember to > pass it manually, and the whole output would be as bad as the > original in case you need the switch. > > I'd rather go with 1., it's easy to implement (we already have partial > flushing with '--events') and it looks like a good compromise on > usability. Thoughts? > I agree with eric. The benefits of buffering are not worth it. Let's just choose a reasonable field width, if something is too big, columns won't line up which i snot a big deal. Unless you come up with a better solution, I am going to revert this.
