Date: Tue, 03 Apr 2018 21:46:21 -0500 From: Larry Rosenman <ler@lerctr.org> To: Cy Schubert <Cy.Schubert@cschubert.com>, Bryan Drewery <bdrewery@FreeBSD.org>, Peter Jeremy <peter@rulingia.com>, Jeff Roberson <jroberson@jroberson.net> Cc: FreeBSD current <freebsd-current@freebsd.org>, Andriy Gapon <avg@freebsd.org> Subject: Re: Strange ARC/Swap/CPU on yesterday's -CURRENT Message-ID: <ADFAA987-75B5-4F37-8393-0F8B5CFFF069@lerctr.org> In-Reply-To: <20180404015345.AFFFC1121@spqr.komquats.com> References: <20180404015345.AFFFC1121@spqr.komquats.com>
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Thanks for that hint. I thought that arc_max was a tunable, but now knowin= g it's sysctl, that helps a lot. --=20 Larry Rosenman http://www.lerctr.org/~ler Phone: +1 214-642-9640 E-Mail: ler@lerctr.org US Mail: 5708 Sabbia Drive, Round Rock, TX 78665-2106 =EF=BB=BFOn 4/3/18, 8:54 PM, "Cy Schubert" <owner-freebsd-current@freebsd.org on = behalf of Cy.Schubert@cschubert.com> wrote: Try arbitrarily reducing arc_max through sysctl. ARC is immediately red= uced and free memory increased however wired pages remains the same. =20 --- Sent using a tiny phone keyboard. Apologies for any typos and autocorrect. Also, this old phone only supports top post. Apologies. =20 Cy Schubert <Cy.Schubert@cschubert.com> or <cy@freebsd.org> The need of the many outweighs the greed of the few. --- =20 -----Original Message----- From: Larry Rosenman Sent: 03/04/2018 19:27 To: Cy Schubert; Bryan Drewery; Peter Jeremy; Jeff Roberson Cc: FreeBSD current; Andriy Gapon Subject: Re: Strange ARC/Swap/CPU on yesterday's -CURRENT =20 When my full backups run (1st Sunday -> Monday of the month) the box be= comes unusable after 5-10 hours of that backup with LOTS of SWAP usage And ARC using 100+G.=20 =20 Is anyone looking into this? =20 =20 =20 --=20 Larry Rosenman http://www.lerctr.org/~ler Phone: +1 214-642-9640 E-Mail: ler@lerctr.org US Mail: 5708 Sabbia Drive, Round Rock, TX 78665-2106 =EF=BB=BFOn 4/3/18, 8:24 PM, "Cy Schubert" <owner-freebsd-current@freebsd.org= on behalf of Cy.Schubert@cschubert.com> wrote: =20 +1 =20 However under certain circumstances it will release some memory. To= reproduce, when bsdtar unpacks some tarballs (when building certain ports) = tar will use 12 GB or more forcing ARC to release memory. =20 BTW, I haven't stopped to grok whether the bsdtar issue is local to= me or another problem yet. =20 --- Sent using a tiny phone keyboard. Apologies for any typos and autocorrect. Also, this old phone only supports top post. Apologies. =20 Cy Schubert <Cy.Schubert@cschubert.com> or <cy@freebsd.org> The need of the many outweighs the greed of the few. --- =20 -----Original Message----- From: Bryan Drewery Sent: 23/03/2018 17:23 To: Peter Jeremy; Jeff Roberson Cc: FreeBSD current; Andriy Gapon Subject: Re: Strange ARC/Swap/CPU on yesterday's -CURRENT =20 On 3/20/2018 12:07 AM, Peter Jeremy wrote: >=20 > On 2018-Mar-11 10:43:58 -1000, Jeff Roberson <jroberson@jroberson= .net> wrote: >> Also, if you could try going back to r328953 or r326346 and let = me know if=20 >> the problem exists in either. That would be very helpful. If a= nyone is=20 >> willing to debug this with me contact me directly and I will sen= d some=20 >> test patches or debugging info after you have done the above ste= ps. >=20 > I ran into this on 11-stable and tracked it to r326619 (MFC of r3= 25851). > I initially got around the problem by reverting that commit but e= ither > it or something very similar is still present in 11-stable r33105= 3. >=20 > I've seen it in my main server (32GB RAM) but haven't managed to = reproduce > it in smaller VBox guests - one difficulty I faced was artificial= ly filling > ARC. >=20 =20 Looking at the ARC change you referred to from r325851 https://reviews.freebsd.org/D12163, I am convinced that ARC backpre= ssure is completely broken. On my 78GB RAM system with ARC limited to 40G= B and doing a poudriere build of all LLVM and GCC packages at once in tmp= fs I can get swap up near 50GB and yet the ARC remains at 40GB through i= t all. It's always been slow to give up memory for package builds bu= t it really seems broken right now. =20 --=20 Regards, Bryan Drewery =20 _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscribe@freeb= sd.org" =20 =20 =20 _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.o= rg" =20
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