Messages in this thread |  | | From | Badari Pulavarty <> | Subject | Re: 2.5.32 IO performance issues | Date | Thu, 29 Aug 2002 13:55:40 -0700 (PDT) |
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> > Badari Pulavarty wrote: > > > > Hi, > > > > I am having severe IO performance problems with 2.5.32 (2.5.31 works fine). > > I was wondering what caused this. > > > > As you can see, IO rate went from > > > > 384MB/sec with 6% CPU utilization on 2.5.31 > > to > > 120MB/sec with 19% CPU utilization on 2.5.32 > > > > ... > > 151712 default_idle 2370.5000 > > 21622 __scsi_end_request 122.8523 > > block-highmem is bust for scsi. (aic7xxx at least). Does > http://www.zip.com.au/~akpm/linux/patches/2.5/2.5.32/2.5.32-mm2/broken-out/scsi_hack.patch > fix it?
Hmm !! This patch fixed it. I remember you gave me this patch for 2.5.31. But 2.5.31 was doing fine without it. But 2.5.32 seem to need it.
procs memory swap io system cpu r b w swpd free buff cache si so bi bo in cs us sy id 1 38 0 0 3811160 0 23532 0 0 384461 0 3981 6346 0 5 95 0 39 0 0 3811152 0 23532 0 0 384499 0 3967 6354 0 5 95 0 39 0 0 3811148 0 23532 0 0 384154 0 3974 6341 0 5 95 0 39 0 0 3811144 0 23532 0 0 384013 0 3964 6344 0 5 95 0 39 0 0 3811204 0 23532 0 0 384154 0 3966 6357 0 5 95 0 39 0 0 3811176 0 23532 0 0 384256 0 3973 6341 0 5 95 0 39 0 0 3811168 0 23532 0 0 384320 0 3969 6329 0 5 95 0 39 0 0 3811152 0 23532 0 0 384294 0 3980 6335 0 5 95
Here is the profile output with this patch:
# readprofile | sort -nr +2 221145 default_idle 3455.3906 3163 do_softirq 16.4740 1489 __scsi_end_request 8.4602 1696 scsi_dispatch_cmd 2.7895 371 dio_bio_complete 2.1080 509 blk_rq_map_sg 1.3255 198 dio_await_one 1.2375 57 dio_prep_bio 1.1875 56 bio_put 1.1667 71 __generic_copy_to_user 1.1094 630 do_direct_IO 0.9157 42 __wake_up 0.8750 297 __set_page_dirty_buffers 0.8438 622 schedule 0.6942 629 __make_request 0.5460 402 get_user_pages 0.5346 17 scsi_sense_valid 0.5312 42 bio_destructor 0.5250 198 bio_alloc 0.4760 32 dio_get_page 0.4000
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