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AJvYcCWIGSMRyfES1HQgfLbLIa/kBRlFYeXlfArLChxKQFvCW8ywGOmw8v14N+MSxr6kLplvmr3BSgXxnQ==@kvack.org X-Gm-Message-State: AOJu0YwfKXDfM7KYIwMWsRT+4+Hu9b095J/86ct3Np42s8vQ4RQr/elW 5wblNg7/0DXE3QA1O8EPd5DRWnzPQraN8CccF4HtZrmtbqmwspkX8cUq5jUc4iJQLUYL13g/sZT SLj/1VNUl9gqFoutTxRSAjsf4zLnyNk4= X-Gm-Gg: ASbGncsBEBgz7MTqTpmlz10c79DAoGWMk5gtJlNIhLDN/4Cv2xJIMaNyG2CAEsNfDko IS2jc1H/N46yyR+48LS75SP3bKWiI0q6srEgmcyFDB5RMpinAZS9RbM0PEYCraQw3b/viIxGIRU e696YG40j1MLXkxTLNCITK2i9ENgZAN/QdC+v7YcAFhWUul3CWxtWW0YQeUycyUeg8V5kaSnQf4 bg6K0kQcDuGL9T4zw2+6fLGxe5BdWLvKYEoGGCrTVYWmoox84AsCX79ba7immeQpwgQGX3Ru+Wd bpQXMS8SFfPnPaj1hg== X-Google-Smtp-Source: AGHT+IEd2S0CoOnsCEqdQWr53aL//daPs2zGPzlplFARXHXFtEQSkqVuew1/vErGx9hY2N+n/Yhj4MUm3fZG4jwvHts= X-Received: by 2002:a05:600c:3b8d:b0:46d:27b7:e7e5 with SMTP id 5b1f17b1804b1-47117917572mr276080945e9.32.1761329342449; Fri, 24 Oct 2025 11:09:02 -0700 (PDT) MIME-Version: 1.0 References: <20251023-fix-slab-accounting-v2-1-0e62d50986ea@suse.cz> In-Reply-To: From: Alexei Starovoitov Date: Fri, 24 Oct 2025 11:08:51 -0700 X-Gm-Features: AWmQ_blsModMP22bdNbVqa2N139hiiPx7zCrnoVxTggAjMOSrvwRYYINiPlR6I0 Message-ID: Subject: Re: [PATCH v2] slab: fix slab accounting imbalance due to defer_deactivate_slab() To: Harry Yoo Cc: Vlastimil Babka , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Alexei Starovoitov , linux-mm , LKML Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 391804000D X-Rspamd-Server: rspam11 X-Rspam-User: X-Stat-Signature: 7tc7uctm8kdrwdsyiehnkmzq74w6d9ru X-HE-Tag: 1761329344-106394 X-HE-Meta: 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 WK0sN1b8 uoioko9zWCawjL0TXVKNd/Z9eUPci+4ucKpJdQs6h7giS+D+mb7jEItkFdFvipixRASH1od5+8+N9G2BAfbiMoOnViBGwJGsJga4FkuTOS3a2K78kiWSzvVMD4i+OSlRAxwrWBGlu71kBwXv+l38JKNMjccRMmQMaOFu/sWmFLa4pSWexQ38Ekw3UhlpHGX36RTVOgcXDotqDTtrJVW/L4uiESYXdo+stajISvvI6mQKpsU0iBr4KTwqSj5smKKkHhIR0twTqKn1UY16XOTfCibbFC48cWhRhT/AxPF8/TyW+dzP5R+UuyotyIUroR+8yyZuqBu5ANiqNbeVsanrarf7pMN5c3wJLGKR7GQt0ZA6552cD2k9b0N690uNsCZzjkn5KA3srK+LuoyDi+KLFtumitKABcj11GtOP4rCNyvg2F/EljiRdW2eLOD8MiANw2e0q 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: List-Subscribe: List-Unsubscribe: On Fri, Oct 24, 2025 at 2:36=E2=80=AFAM Harry Yoo wr= ote: > > > > > Note that deactivate_slab() contains VM_BUG_ON(!old.frozen); > > we would have seen this triggered if we were passing unfrozen slabs to > > (defer_)deactivate_slab(). I assume it's also why the "unlucky, discard= " > > code marks it frozen before calling defer_deactivate_slab() (and this p= atch > > removes that). Yes, exactly, since that's what deactivate_slab() wants to see. > > So I think we're fine? > > Yes. All my concerns were answered. I guess I understand it enough now to: Acked-by: Alexei Starovoitov