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h=Date:From:To:Cc:Subject:In-Reply-To:References; b=ZKaH01ifMY4i78+8eAJ7lZTV+LQIL/XWqKn44DS2+UVEgj25WFu316wKVzIXqwzp+ ERdY7Kwmp8rOrSujjnTZMfaihqx/JI14pn3lMBoRB2mUgcJiPAz5BbHJZh57N1phlh hKjaODtluC+q6YbbehddLGUqISmTYpG4v33r1L4E= Date: Mon, 31 Aug 2026 17:02:33 -0700 From: Andrew Morton To: David Stevens Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] memcg: Don't call schedule_work when no spinning is allowed Message-Id: <20260831170233.e3deb2a546722a3c664bcd98@linux-foundation.org> In-Reply-To: <20260831234339.280376-1-stevensd@google.com> References: <20260831234339.280376-1-stevensd@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Stat-Signature: yi46oss1rqbao1x55d96m3kw5xe6p59q X-Rspamd-Queue-Id: 76F6B40003 X-Rspamd-Server: rspam06 X-HE-Tag: 1788220955-457247 X-HE-Meta: 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 Tkms25LR bVUxYrz1qDBl8kArMuTtP+euQsNJoKv1s8g7hNU5Ya1VbBtO8c+mMYaRB5RhJJoQyX5s9WKIrjKHL1ENSoNh0RrltLM8c2oYlirUmmKcLVoBzYbkZFXZ53+BNdGwGECOAT5mlDN6Tp1h1Vndxp0dhKDPeMgN0x4ooICJi+CA2iUTTfpjy6+oW9IlgqS/+QIQMOl+sXtLyei4jc6O3ChHe+q7j5P6r25YMWLIbW5L6xTvGBql2Kj2PPtyEuVhIpYRvP1+Cc02I+QGwENb6uLsHAKeOr5Mx4frBJWvOJLIHOK+ETfJVhUy59W+4z3hKyUy/oRru Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 31 Aug 2026 16:43:39 -0700 David Stevens wrote: > Memcg charging can be done from any context, but calling schedule_work() > isn't safe from an NMI. Who does that. bpf, IIRC? > If memory.high is breached from a context where > spinning isn't allowed, use irq_work to schedule the reclaim work. > > Fixes: 3ac4638a734a ("memcg: make memcg_rstat_updated nmi safe") Can anything actually hit this? IOW, should we backport it? > Signed-off-by: David Stevens