[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 1/3] xen: move debugtrace coding to common/debugtrace.c
On 28.07.2019 10:40, Juergen Gross wrote: > @@ -1155,178 +1155,6 @@ int printk_ratelimit(void) > return __printk_ratelimit(printk_ratelimit_ms, printk_ratelimit_burst); > } > > -/* > - * ************************************************************** > - * *************** Serial console ring buffer ******************* > - * ************************************************************** > - */ I acknowledge that this comment has at best been displaced from what it would properly belong to, so is indeed perhaps best dropped. But ... > -#ifdef CONFIG_DEBUG_TRACE > - > -/* Send output direct to console, or buffer it? */ > -static volatile int debugtrace_send_to_console; > - > -static char *debugtrace_buf; /* Debug-trace buffer */ > -static unsigned int debugtrace_prd; /* Producer index */ > -static unsigned int debugtrace_kilobytes = 128, debugtrace_bytes; > -static unsigned int debugtrace_used; > -static DEFINE_SPINLOCK(debugtrace_lock); > -integer_param("debugtrace", debugtrace_kilobytes); > - > -static void debugtrace_dump_worker(void) > -{ > - if ( (debugtrace_bytes == 0) || !debugtrace_used ) > - return; > - > - printk("debugtrace_dump() starting\n"); > - > - /* Print oldest portion of the ring. */ > - ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); > - sercon_puts(&debugtrace_buf[debugtrace_prd]); > - > - /* Print youngest portion of the ring. */ > - debugtrace_buf[debugtrace_prd] = '\0'; > - sercon_puts(&debugtrace_buf[0]); > - > - memset(debugtrace_buf, '\0', debugtrace_bytes); > - > - printk("debugtrace_dump() finished\n"); > -} > - > -static void debugtrace_toggle(void) > -{ > - unsigned long flags; > - > - watchdog_disable(); > - spin_lock_irqsave(&debugtrace_lock, flags); > - > - /* > - * Dump the buffer *before* toggling, in case the act of dumping the > - * buffer itself causes more printk() invocations. > - */ > - printk("debugtrace_printk now writing to %s.\n", > - !debugtrace_send_to_console ? "console": "buffer"); > - if ( !debugtrace_send_to_console ) > - debugtrace_dump_worker(); > - > - debugtrace_send_to_console = !debugtrace_send_to_console; > - > - spin_unlock_irqrestore(&debugtrace_lock, flags); > - watchdog_enable(); > - > -} > - > -void debugtrace_dump(void) > -{ > - unsigned long flags; > - > - watchdog_disable(); > - spin_lock_irqsave(&debugtrace_lock, flags); > - > - debugtrace_dump_worker(); > - > - spin_unlock_irqrestore(&debugtrace_lock, flags); > - watchdog_enable(); > -} > - > -static void debugtrace_add_to_buf(char *buf) > -{ > - char *p; > - > - for ( p = buf; *p != '\0'; p++ ) > - { > - debugtrace_buf[debugtrace_prd++] = *p; > - /* Always leave a nul byte at the end of the buffer. */ > - if ( debugtrace_prd == (debugtrace_bytes - 1) ) > - debugtrace_prd = 0; > - } > -} > - > -void debugtrace_printk(const char *fmt, ...) > -{ > - static char buf[1024], last_buf[1024]; > - static unsigned int count, last_count, last_prd; > - > - char cntbuf[24]; > - va_list args; > - unsigned long flags; > - > - if ( debugtrace_bytes == 0 ) > - return; > - > - debugtrace_used = 1; > - > - spin_lock_irqsave(&debugtrace_lock, flags); > - > - ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); > - > - va_start(args, fmt); > - vsnprintf(buf, sizeof(buf), fmt, args); > - va_end(args); > - > - if ( debugtrace_send_to_console ) > - { > - snprintf(cntbuf, sizeof(cntbuf), "%u ", ++count); > - serial_puts(sercon_handle, cntbuf); > - serial_puts(sercon_handle, buf); > - } > - else > - { > - if ( strcmp(buf, last_buf) ) > - { > - last_prd = debugtrace_prd; > - last_count = ++count; > - safe_strcpy(last_buf, buf); > - snprintf(cntbuf, sizeof(cntbuf), "%u ", count); > - } > - else > - { > - debugtrace_prd = last_prd; > - snprintf(cntbuf, sizeof(cntbuf), "%u-%u ", last_count, ++count); > - } > - debugtrace_add_to_buf(cntbuf); > - debugtrace_add_to_buf(buf); > - } > - > - spin_unlock_irqrestore(&debugtrace_lock, flags); > -} > - > -static void debugtrace_key(unsigned char key) > -{ > - debugtrace_toggle(); > -} > - > -static int __init debugtrace_init(void) > -{ > - int order; > - unsigned int kbytes, bytes; > - > - /* Round size down to next power of two. */ > - while ( (kbytes = (debugtrace_kilobytes & (debugtrace_kilobytes-1))) != > 0 ) > - debugtrace_kilobytes = kbytes; > - > - bytes = debugtrace_kilobytes << 10; > - if ( bytes == 0 ) > - return 0; > - > - order = get_order_from_bytes(bytes); > - debugtrace_buf = alloc_xenheap_pages(order, 0); > - ASSERT(debugtrace_buf != NULL); > - > - memset(debugtrace_buf, '\0', bytes); > - > - debugtrace_bytes = bytes; > - > - register_keyhandler('T', debugtrace_key, > - "toggle debugtrace to console/buffer", 0); > - > - return 0; > -} > -__initcall(debugtrace_init); > - > -#endif /* !CONFIG_DEBUG_TRACE */ > - > - > /* > * ************************************************************** > * *************** Debugging/tracing/error-report *************** ... what about this one? There's only panic() between it and the next such comment, and I don't think the "Debugging/tracing" part of it are applicable (anymore). > --- a/xen/include/xen/console.h > +++ b/xen/include/xen/console.h > @@ -48,4 +48,8 @@ int console_resume(void); > > extern int8_t opt_console_xen; > > +/* Issue string via serial line. */ > +extern int sercon_handle; > +void sercon_puts(const char *s); I guess avoiding their exposure was one of the reasons the debug trace code lived in the place you move it from. I'm unconvinced non-console code is actually supposed to make use of either, but I'm not opposed enough to nak the change. I don't think though the comment fits well with the variable declaration. Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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