Re: [libvirt] [PATCH v2] Allow to dynamically set the size of the debug buffer

Allow to dynamically set the size of the debug buffer This is the part allowing to dynamically resize the debug log buffer from it's default 64kB size. The buffer is now dynamically allocated. It adds a new API virLogSetBufferSize() which resizes the buffer If passed a zero size, the buffer is deallocated and we do the small optimization of not formatting messages which are not output anymore. On the daemon side, it just adds a new option log_buffer_size to libvirtd.conf and call virLogSetBufferSize() if needed * src/util/logging.h src/util/logging.c src/libvirt_private.syms: make buffer dynamic and add virLogSetBufferSize() internal API * daemon/libvirtd.conf: document the new log_buffer_size option * daemon/libvirtd.c: read and use the new log_buffer_size option diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c index 452566c..ad3274f 100644 --- a/daemon/libvirtd.c +++ b/daemon/libvirtd.c @@ -2713,18 +2713,22 @@ remoteReadSaslAllowedUsernameList (virConfPtr conf ATTRIBUTE_UNUSED, * Set up the logging environment * By default if daemonized all errors go to the logfile libvirtd.log, * but if verbose or error debugging is asked for then also output - * informations or debug. + * informations or debug. Default size if 64 kB.

+++ b/src/util/logging.c @@ -36,6 +36,7 @@ #endif #include "ignore-value.h" +#include "virterror_internal.h" #include "logging.h" #include "memory.h" #include "util.h" @@ -43,6 +44,8 @@ #include "threads.h" #include "files.h" +#define VIR_FROM_THIS VIR_FROM_NONE

@@ -192,15 +197,85 @@ int virLogStartup(void) { virLogInitialized = 1; virLogLock(); + if (VIR_ALLOC_N(virLogBuffer, virLogSize) < 0) { + /* + * The debug buffer is not a critical component, allow startup + * even in case of failure to allocate it in case of a + * configuration mistake. + */ + virLogSize = 64000;

+ if (VIR_ALLOC_N(virLogBuffer, virLogSize) < 0) { + pbm = "Failed to allocate debug buffer: desactivating debug log\n";