Messages in this thread | | | Date | Thu, 03 Dec 2009 10:55:41 -0600 | From | "Chris Friesen" <> | Subject | Re: seeing strange values for tcp sk_rmem_alloc |
| |
On 12/01/2009 11:52 AM, Eric Dumazet wrote:
> But be careful of sender tcp stack : It might be delayed a bit, > because it waits for receiver to open its window (slow start) > > You probably need something like > > while (1) { > send(fd1, buffer, 2Kbytes); > sleep(2); // let tcp stack flush its write buffers > display_sk_rmem_alloc(fd2); > }
Ah, that makes a difference. But the results (see below) still look odd. For this test, /proc/sys/net/core/rmem_default is 118784. For some reason sk_rmem_alloc gets bumped by 16KB when I only send 2KB of data, and it drops back down again every 6 packets.
Chris
used: 16848 used: 33696 used: 50544 used: 67392 used: 84240 used: 101088 used: 30736 used: 47584 used: 64432 used: 81280 used: 98128 used: 114976 used: 44624 used: 61472 used: 78320 used: 95168 used: 112016 used: 128864 used: 58512 used: 75360 used: 92208 used: 109056 used: 125904 used: 142752 used: 72400 used: 89248 used: 106096 used: 122944 used: 139792 used: 156640 used: 86288 used: 103136 used: 119984 used: 136832 used: 153680 used: 170528 used: 100176 used: 117024 used: 133872 used: 150720 used: 167568 used: 184416 used: 114064 used: 130912 used: 147760 used: 164608 used: 181456 used: 198304 used: 127952 used: 144800 used: 161648 used: 178496 used: 195344 used: 212192 used: 141840 used: 158688 used: 175536 used: 192384 used: 209232 used: 226080 used: 155728 used: 172576 used: 189424 used: 206272 used: 223120 used: 239968 used: 169616 used: 186464 used: 203312 used: 220160 used: 237008 used: 253856 used: 183504 used: 200352 used: 217200 used: 234048 used: 250896 used: 267744 used: 197392 used: 214240 used: 231088 used: 247936 used: 264784 used: 281632 used: 211280 used: 228128 used: 244976
| |