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[209.85.167.48]) by smtp.gmail.com with ESMTPSA id x4sm4463836ljd.34.2020.08.03.10.56.34 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 Aug 2020 10:56:34 -0700 (PDT) Received: by mail-lf1-f48.google.com with SMTP id b30so20927664lfj.12 for ; Mon, 03 Aug 2020 10:56:34 -0700 (PDT) X-Received: by 2002:ac2:46d0:: with SMTP id p16mr9323974lfo.142.1596477394160; Mon, 03 Aug 2020 10:56:34 -0700 (PDT) MIME-Version: 1.0 References: <20200723124749.GA7428@redhat.com> <20200724152424.GC17209@redhat.com> <20200803131453.GL5174@dhcp22.suse.cz> In-Reply-To: <20200803131453.GL5174@dhcp22.suse.cz> From: Linus Torvalds Date: Mon, 3 Aug 2020 10:56:17 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH] mm: silence soft lockups from unlock_page To: Michal Hocko Cc: Oleg Nesterov , Hugh Dickins , Linux-MM , LKML , Andrew Morton , Tim Chen Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 8303810097AA4 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Aug 3, 2020 at 6:14 AM Michal Hocko wrote: > > I hope I got it right and this is the latest version of your patches. Btw. > do you still think that increasing PAGE_WAIT_TABLE_BITS is reasonable. I suspect it's still very reasonable, but I'd love to have numbers for it. > In the meantime I have learned that the customer suffering from the > issue is very unlikely to reboot the machine anytime soon or even > willing to test a non-trivial patch. We do not own any machine which > exhibit this problem unfortunately. So it is quite unlikely I can > help with testing. Ok. > Also does it make sense to put this into mmotm tree for a while to get a > larger testing coverage? Well, I did the 5.8 release yesterday, so I just put it in the tree for the 5.9 merge window - I've been running it locally since I posted it, and while Hugh couldn't prove it improved anything, his results certainly also didn't say it was bad. So anybody that tests my top-of-tree will be testing that thing now, which is likely more than linux-next or mmotm gets (outside of build testing and the robots). Of course, I don't know how many people run my development tree, particularly during the busy merge window, but hey, at worst it will be in the next linux-next that way. At best, it's not just me, but a number of other developers. Linus