Re: whats going on with the scheduler?

On Mon, 7 Jul 2003, Dan Nelson wrote:

> Not if it's ssh that's holding Giant for longer than it should.   The
> setiathome processes may be calling some really fast syscall 500 times
> a second which doesn't cause a problem until ssh comes along and calls
> some other syscall that takes .1 ms to return but also locks Giant long
> enough to cause the other processes to all back up behind it.

setiathome seems to only make syscalls once every few seconds:

50.625740361 open("outfile.sah",0x0,0666)        = 5 (0x5)
50.632149151 fstat(5,0xbfbff7bc)                 = 0 (0x0)
50.638742382 fstat(5,0xbfbff874)                 = 0 (0x0)
50.646472300 lseek(5,0x0,1)                      = 0 (0x0)
50.654260852 lseek(5,0x0,0)                      = 0 (0x0)
50.660798154 read(0x5,0xe65000,0x4000)           = 3756 (0xeac)
50.667928862 close(5)                            = 0 (0x0)
50.674330474 getrusage(0x0,0xbfbff994)           = 0 (0x0)
50.685590259 open("outfile.sah",0x0,0666)        = 5 (0x5)
50.694391188 fstat(5,0xbfbff7ac)                 = 0 (0x0)
50.703441591 fstat(5,0xbfbff864)                 = 0 (0x0)
50.711881896 lseek(5,0x0,1)                      = 0 (0x0)
50.719670900 lseek(5,0x0,0)                      = 0 (0x0)
50.725983906 read(0x5,0xd64000,0x4000)           = 3756 (0xeac)
50.732710339 close(5)                            = 0 (0x0)
54.227980065 open("outfile.sah",0x0,0666)        = 5 (0x5)
54.234289708 fstat(5,0xbfbff7bc)                 = 0 (0x0)
54.241518075 fstat(5,0xbfbff874)                 = 0 (0x0)
54.249555307 lseek(5,0x0,1)                      = 0 (0x0)
54.257416703 lseek(5,0x0,0)                      = 0 (0x0)
54.263766467 read(0x5,0xe65000,0x4000)           = 3756 (0xeac)
54.270554826 close(5)                            = 0 (0x0)
54.276730780 getrusage(0x0,0xbfbff994)           = 0 (0x0)
54.286228233 open("outfile.sah",0x0,0666)        = 5 (0x5)
54.292575368 fstat(5,0xbfbff7ac)                 = 0 (0x0)
54.299568244 fstat(5,0xbfbff864)                 = 0 (0x0)
54.313140514 lseek(5,0x0,1)                      = 0 (0x0)
54.320997075 lseek(5,0x0,0)                      = 0 (0x0)
54.327394776 read(0x5,0xd64000,0x4000)           = 3756 (0xeac)
54.334797742 close(5)                            = 0 (0x0)
57.830104692 open("outfile.sah",0x0,0666)        = 5 (0x5)
57.836412958 fstat(5,0xbfbff7bc)                 = 0 (0x0)
57.842768341 fstat(5,0xbfbff874)                 = 0 (0x0)
57.850834611 lseek(5,0x0,1)                      = 0 (0x0)
57.862301512 lseek(5,0x0,0)                      = 0 (0x0)
57.868723869 read(0x5,0xe65000,0x4000)           = 3756 (0xeac)
57.875396846 close(5)                            = 0 (0x0)
57.881638118 getrusage(0x0,0xbfbff994)           = 0 (0x0)
57.890991955 open("outfile.sah",0x0,0666)        = 5 (0x5)
57.897344227 fstat(5,0xbfbff7ac)                 = 0 (0x0)
57.903621248 fstat(5,0xbfbff864)                 = 0 (0x0)
57.913178984 lseek(5,0x0,1)                      = 0 (0x0)
57.922614702 lseek(5,0x0,0)                      = 0 (0x0)
57.931253628 read(0x5,0xd64000,0x4000)           = 3756 (0xeac)
57.938755028 close(5)                            = 0 (0x0)


--

 :{ andyf_at_speednet.com.au

        Andy Farkas
    System Administrator
   Speednet Communications
 http://www.speednet.com.au/