Date: Sat, 12 Oct 2013 21:17:46 -0500 From: Pedro Giffuni <pfg@FreeBSD.org> To: dtrace@FreeBSD.org Subject: Re: Dtrace providers wanted list Message-ID: <6A4B05EA-D9C7-4014-BF86-4676EF01071C@FreeBSD.org> In-Reply-To: <52596B73.2050702@FreeBSD.org> References: <52546385.2050203@FreeBSD.org> <20131010042544.GB65451@raichu> <52596B73.2050702@FreeBSD.org>
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Il giorno 12/ott/2013, alle ore 10:32, Pedro Giffuni <pfg@FreeBSD.org> = ha scritto: > On 09.10.2013 23:25, Mark Johnston wrote: >> On Tue, Oct 08, 2013 at 02:56:53PM -0500, Pedro Giffuni wrote: >>> Hello; >>>=20 >>> Sometime ago I looked around the list of Oracle's DTrace providers. >>>=20 >>> https://wikis.oracle.com/display/DTrace/Providers >>>=20 >>> We absolutely want them and although extremely useful as it is, = DTrace >>> won't be complete until we have them all ;). For the time being we >>> should probably focus on getting the really critical ones though. >>>=20 >>> The first in the list that we don't have that I think is critical is >>> mentioned in Brendan Gregg's FreeBSD specific blog post: >>>=20 >>> = http://dtrace.org/blogs/brendan/2013/09/25/the-use-method-freebsd-performa= nce-checklist/ >>>=20 >>> "Tracing paging is tricker until the vminfo provider is added; you = could >>> try tracing from swap_pager_putpages() and swap_pager_getpages(), = but I >>> didn=92t see an easy way to walk back to a thread struct; another = approach >>> may be via vm_fault_hold(). Good luck. ..." >=20 > I started looking at this but it is somewhat more work than expected: > Solaris has a specific vminfo interface in sysinfo.h. It looks very = handy > for providing general vm statistics but our vm is different and I am > not sure we want to go into implementing such interface. It depends > on a VM guru, anyways. >=20 > OTOH, I found the fsinfo provider: >=20 > = https://bitbucket.org/illumos/illumos-gate/commits/5b50c2dcfdf948c4e4f0b88= 0eb76210067e7af7c >=20 > Our VFS does have some similarity so this may be easier/doable, plus > it may be needed by the scsi and ZFS providers. Ugh =85 I looked at this one too, and similarly to the vminfo provider, there is = a vopstats structure in vnode.h that we don't have. Both the vopstats and vminfo structures are used to support Solaris' = kstat(1M) utility. In other words, this is an in kernel system made to report statistics. = While it seems natural to use them for DTrace in Solaris, we would have to = reimplement it in some way if we want to have equivalent providers in FreeBSD. :-( I am afraid that the CPC Provider may have similar issues but I haven't = looked at it. Pedro.
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