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[109.81.89.64]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5d7e5ceff0bsm1303313a12.65.2024.12.18.03.32.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 18 Dec 2024 03:32:43 -0800 (PST) Date: Wed, 18 Dec 2024 12:32:42 +0100 From: Michal Hocko To: alexei.starovoitov@gmail.com Cc: bpf@vger.kernel.org, andrii@kernel.org, memxor@gmail.com, akpm@linux-foundation.org, peterz@infradead.org, vbabka@suse.cz, bigeasy@linutronix.de, rostedt@goodmis.org, houtao1@huawei.com, hannes@cmpxchg.org, shakeel.butt@linux.dev, willy@infradead.org, tglx@linutronix.de, jannh@google.com, tj@kernel.org, linux-mm@kvack.org, kernel-team@fb.com Subject: Re: [PATCH bpf-next v3 4/6] memcg: Use trylock to access memcg stock_lock. Message-ID: References: <20241218030720.1602449-1-alexei.starovoitov@gmail.com> <20241218030720.1602449-5-alexei.starovoitov@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241218030720.1602449-5-alexei.starovoitov@gmail.com> On Tue 17-12-24 19:07:17, alexei.starovoitov@gmail.com wrote: > From: Alexei Starovoitov > > Teach memcg to operate under trylock conditions when > spinning locks cannot be used. Can we make this trylock unconditional? I hope I am not really missing anything important but if the local_lock is just IRQ disabling on !RT. For RT this is more involved but does it make sense to spin/sleep on the cache if we can go ahead and charge directly to counters? I mean doesn't this defeat the purpose of the cache in the first place? -- Michal Hocko SUSE Labs