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Goncalves" , Andrew Morton , Mel Gorman , Thomas Gleixner Subject: Re: [PATCH] mm/page_alloc: Use write_seqlock_irqsave() instead write_seqlock() + local_irq_save(). Message-ID: References: <8b6d3f39-c573-ca2b-957b-8c48c2fa68ad@I-love.SAKURA.ne.jp> <20230623094544.RcLNdg6H@linutronix.de> <20230623101111.7tuAg5p5@linutronix.de> <115cf90c-5bc5-d4b0-6489-d1ee5735194a@I-love.SAKURA.ne.jp> <20230623124416.M8fKvITC@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230623124416.M8fKvITC@linutronix.de> X-Rspamd-Queue-Id: D240280004 X-Rspam-User: X-Rspamd-Server: rspam02 X-Stat-Signature: zb5oghqzs9hm75jq1ai3m9ebhi3ohgq1 X-HE-Tag: 1687525030-710866 X-HE-Meta: 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 OTiS6mO3 QNbkH2FQfZaHpywhEMOycsuXgmRYYXSZ6sRrKwhNOt4wV1NjaxL0YJoPtbefMVCf3cXfgewvHm5Q9eXNyDnDhYbBgBEONue81d27EjSO7NCywHTBHKIMMMYhDc8lF2dPInBsDNVJ0cffF5qKPxtZ0/XStUc3rPrRl3oomTQSBYt3h5GAaqbzloCrRebF8roEQWneC 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 Fri 23-06-23 14:44:16, Sebastian Andrzej Siewior wrote: [...] > > Hmm, I feel worried that kmalloc(GFP_ATOMIC) from hard IRQ context > > might sleep if RT... > > Relax and don't worry. PREEMPT_RT does not allow (or has afaik) memory > allocations from hard IRQ context (or preempt-disable sections). Yeah, that would require something like GFP_LOCKLESS or change some of the locking we have to raw spinlocks. -- Michal Hocko SUSE Labs