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Biederman) To: Michal Hocko Cc: Kirill Tkhai , akpm@linux-foundation.org, peterz@infradead.org, oleg@redhat.com, viro@zeniv.linux.org.uk, mingo@kernel.org, paulmck@linux.vnet.ibm.com, keescook@chromium.org, riel@redhat.com, tglx@linutronix.de, kirill.shutemov@linux.intel.com, marcos.souza.org@gmail.com, hoeun.ryu@gmail.com, pasha.tatashin@oracle.com, gs051095@gmail.com, dhowells@redhat.com, rppt@linux.vnet.ibm.com, linux-kernel@vger.kernel.org References: <152473763015.29458.1131542311542381803.stgit@localhost.localdomain> <20180426130700.GP17484@dhcp22.suse.cz> Date: Thu, 26 Apr 2018 11:19:33 -0500 In-Reply-To: <20180426130700.GP17484@dhcp22.suse.cz> (Michal Hocko's message of "Thu, 26 Apr 2018 15:07:00 +0200") Message-ID: <87efj2q6sq.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1fBjdk-00046F-T4;;;mid=<87efj2q6sq.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=97.119.174.25;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18GJcmTpH5m6JDbFw/QRGEx3BqHLlxcJIg= X-SA-Exim-Connect-IP: 97.119.174.25 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on sa08.xmission.com X-Spam-Level: ** X-Spam-Status: No, score=2.5 required=8.0 tests=ALL_TRUSTED,BAYES_50, DCC_CHECK_NEGATIVE,T_TM2_M_HEADER_IN_MSG,T_TooManySym_01,T_TooManySym_02, T_TooManySym_03,XMGappySubj_01,XMNoVowels,XMSubLong autolearn=disabled version=3.4.1 X-Spam-Report: * -1.0 ALL_TRUSTED Passed through trusted hosts only via SMTP * 0.5 XMGappySubj_01 Very gappy subject * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.7 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: No description available. * 0.8 BAYES_50 BODY: Bayes spam probability is 40 to 60% * [score: 0.4999] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa08 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.0 T_TooManySym_03 6+ unique symbols in subject X-Spam-DCC: XMission; sa08 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: **;Michal Hocko X-Spam-Relay-Country: X-Spam-Timing: total 165 ms - load_scoreonly_sql: 0.04 (0.0%), signal_user_changed: 4.4 (2.6%), b_tie_ro: 3.4 (2.1%), parse: 0.96 (0.6%), extract_message_metadata: 2.5 (1.5%), get_uri_detail_list: 0.76 (0.5%), tests_pri_-1000: 3.5 (2.1%), tests_pri_-950: 1.16 (0.7%), tests_pri_-900: 1.04 (0.6%), tests_pri_-400: 17 (10.5%), check_bayes: 16 (9.9%), b_tokenize: 4.2 (2.5%), b_tok_get_all: 6 (3.5%), b_comp_prob: 1.22 (0.7%), b_tok_touch_all: 3.0 (1.8%), b_finish: 0.74 (0.4%), tests_pri_0: 123 (74.1%), check_dkim_signature: 0.36 (0.2%), check_dkim_adsp: 2.6 (1.6%), tests_pri_500: 3.7 (2.2%), rewrite_mail: 0.00 (0.0%) Subject: Re: [PATCH 0/4] exit: Make unlikely case in mm_update_next_owner() more scalable X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michal Hocko writes: > I've had a patch to remove owner few years back. It needed some work > to finish but maybe that would be a better than try to make > non-scalable thing suck less. I have a question. Would it be reasonable to just have a mm->memcg? That would appear to be the simplest solution to the problem. That would require failing migration between memory cgroups if you are not moving all of processes/threads that have a given mm_struct. That should not be a huge restriction as typically it is only threads that share a mm. Further the check should be straigh forward: counting the number of threads and verifying the count matches the count on the mm_struct. Eric