On Wed, Jan 23, 2013 at 06:37:56PM -0300, Ezequiel Garcia wrote: > Hi Minchan, > > On Wed, Jan 23, 2013 at 1:27 AM, Minchan Kim <minchan@xxxxxxxxxx> wrote: > > Hi Ezequiel, > > > > On Tue, Jan 22, 2013 at 06:46:58AM -0300, Ezequiel Garcia wrote: > >> From: Ezequiel Garcia <elezegarcia@xxxxxxxxx> > >> > >> The purpose of trace_analyze.py tool is to perform static > >> and dynamic memory analysis using a kmem ftrace > >> log file and a built kernel tree. > >> > >> This script and related work has been done on the CEWG/2012 project: > >> "Kernel dynamic memory allocation tracking and reduction" > >> (More info here [1]) > >> > >> It produces mainly two kinds of outputs: > >> * an account-like output, similar to the one given by Perf, example below. > >> * a ring-char output, examples here [2]. > >> > >> $ ./scripts/tracing/trace_analyze.py -k linux -f kmem.log --account-file account.txt > >> $ ./scripts/tracing/trace_analyze.py -k linux -f kmem.log -c account.txt > >> > >> This will produce an account file like this: > >> > >> current bytes allocated: 669696 > >> current bytes requested: 618823 > >> current wasted bytes: 50873 > >> number of allocs: 7649 > >> number of frees: 2563 > >> number of callers: 115 > >> > >> total waste net alloc/free caller > >> --------------------------------------------- > >> 299200 0 298928 1100/1 alloc_inode+0x4fL > >> 189824 0 140544 1483/385 __d_alloc+0x22L > >> 51904 0 47552 811/68 sysfs_new_dirent+0x4eL > >> [...] > >> > >> [1] http://elinux.org/Kernel_dynamic_memory_analysis > >> [2] http://elinux.org/Kernel_dynamic_memory_analysis#Current_dynamic_footprint > > > > First of all, Thanks for nice work! It could be very useful for > > embedded side. > > > > Questions. > > > > 1. Can we detect different call path but same function? > > I mean > > > > A C > > \ / > > B D > > \ / > > E > > | > > kmalloc > > > > In this case, E could be called by A or C. I would like to know the call path. > > It could point out exact culprit of memory hogger. > > > > I'm sorry, I'm not following you: > How can I know which caller in the call path is the 'real' responsible > for the allocation? > > The only way I can think of achieving something like this is by using > kmalloc_track_caller() instead of kmalloc(). > This is done in cases where an allocer is known to alloc memory on > behalf of its caller. I mean following as. It's a example from page_owner about alloc_pages. I'm not sure it's good example but it could give my intent. 358 times: Page allocated via order 1, mask 0x2852d0 [<ffffffff811654f5>] new_slab+0x2d5/0x370 [<ffffffff815705a8>] __slab_alloc+0x2bb/0x41c [<ffffffff811682ac>] kmem_cache_alloc+0x18c/0x1a0 [<ffffffff8118ac07>] __d_alloc+0x27/0x180 [<ffffffff8118b038>] d_alloc+0x28/0x80 [<ffffffff8117d313>] lookup_dcache+0xa3/0xd0 [<ffffffff8117d363>] __lookup_hash+0x23/0x50 [<ffffffff8157076a>] lookup_slow+0x49/0xad .. .. 1 times: Page allocated via order 1, mask 0x2852d0 [<ffffffff811654f5>] new_slab+0x2d5/0x370 [<ffffffff815705a8>] __slab_alloc+0x2bb/0x41c [<ffffffff811682ac>] kmem_cache_alloc+0x18c/0x1a0 [<ffffffff8118ac07>] __d_alloc+0x27/0x180 [<ffffffff8118b038>] d_alloc+0x28/0x80 [<ffffffff8117d313>] lookup_dcache+0xa3/0xd0 [<ffffffff8117d363>] __lookup_hash+0x23/0x50 [<ffffffff81181126>] lookup_one_len+0xd6/0x130 >From above example, alloc_pages could be called from several path The one path is lookup_slow and another is lookup_one_len so I can investigate who asks lookup_slow frequently. > > > 2. Does it support alloc_pages family? > > kmem event trace already supports it. If it supports, maybe we can replace > > CONFIG_PAGE_OWNER hack. > > > > Mmm.. no, it doesn't support alloc_pages and friends, for we found > no reason to do it. > However, it sounds like a nice idea, on a first thought. > > I'll review CONFIG_PAGE_OWNER patches and see if I can come up with something. Thanks! > > Meantime, and given this is just a script submission, is there anything > preventing to merge this? We can move it to perf, and/or add it > features, etc. later, > on top of this. Does this make sense? > > -- > Ezequiel > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>