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Piccoli" , "Paul E. McKenney" , linuxppc-dev@lists.ozlabs.org, kexec@lists.infradead.org Subject: Re: [PATCH next v1 2/3] printk: remove safe buffers Message-ID: References: <20210316233326.10778-1-john.ogness@linutronix.de> <20210316233326.10778-3-john.ogness@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210316233326.10778-3-john.ogness@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (21/03/17 00:33), John Ogness wrote: [..] > void printk_nmi_direct_enter(void) > { > @@ -324,27 +44,8 @@ void printk_nmi_direct_exit(void) > this_cpu_and(printk_context, ~PRINTK_NMI_DIRECT_CONTEXT_MASK); > } > > -#else > - > -static __printf(1, 0) int vprintk_nmi(const char *fmt, va_list args) > -{ > - return 0; > -} > - > #endif /* CONFIG_PRINTK_NMI */ > > -/* > - * Lock-less printk(), to avoid deadlocks should the printk() recurse > - * into itself. It uses a per-CPU buffer to store the message, just like > - * NMI. > - */ > -static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args) > -{ > - struct printk_safe_seq_buf *s = this_cpu_ptr(&safe_print_seq); > - > - return printk_safe_log_store(s, fmt, args); > -} > - > /* Can be preempted by NMI. */ > void __printk_safe_enter(void) > { > @@ -369,7 +70,10 @@ __printf(1, 0) int vprintk_func(const char *fmt, va_list args) > * Use the main logbuf even in NMI. But avoid calling console > * drivers that might have their own locks. > */ > - if ((this_cpu_read(printk_context) & PRINTK_NMI_DIRECT_CONTEXT_MASK)) { > + if (this_cpu_read(printk_context) & > + (PRINTK_NMI_DIRECT_CONTEXT_MASK | > + PRINTK_NMI_CONTEXT_MASK | > + PRINTK_SAFE_CONTEXT_MASK)) { Do we need printk_nmi_direct_enter/exit() and PRINTK_NMI_DIRECT_CONTEXT_MASK? Seems like all printk_safe() paths are now DIRECT - we store messages to the prb, but don't call console drivers. -ss