From 2fd92c3d6c7fba9a28ce4779ff6623dc911e7b78 Mon Sep 17 00:00:00 2001 From: Matthew Ahrens Date: Wed, 21 Mar 2018 15:37:32 -0700 Subject: [PATCH] enable zfs_dbgmsg() by default, without dprintf() zfs_dbgmsg() should record a message by default. As a general principal, these messages shouldn't be too verbose. Furthermore, the amount of memory used is limited to 4MB (by default). dprintf() should only record a message if this is a debug build, and ZFS_DEBUG_DPRINTF is set in zfs_flags. This flag is not set by default (even on debug builds). These messages are extremely verbose, and sometimes nontrivial to compute. SET_ERROR() should only record a message if ZFS_DEBUG_SET_ERROR is set in zfs_flags. This flag is not set by default (even on debug builds). This brings our behavior in line with illumos. Note that the message format is unchanged (including file, line, and function, even though these are not recorded on illumos). Reviewed-by: Giuseppe Di Natale Reviewed-by: Brian Behlendorf Reviewed-by: Prakash Surya Signed-off-by: Matthew Ahrens Closes #7314 --- include/sys/zfs_debug.h | 19 ++++++++++++++++--- module/zfs/arc.c | 2 ++ module/zfs/dmu_send.c | 2 ++ module/zfs/spa_misc.c | 3 +-- module/zfs/zfs_debug.c | 40 +++++++++++++++++----------------------- 5 files changed, 38 insertions(+), 28 deletions(-) diff --git a/include/sys/zfs_debug.h b/include/sys/zfs_debug.h index 226aaa2b8..7e05c2a35 100644 --- a/include/sys/zfs_debug.h +++ b/include/sys/zfs_debug.h @@ -41,6 +41,7 @@ extern "C" { extern int zfs_flags; extern int zfs_recover; extern int zfs_free_leak_on_eio; +extern int zfs_dbgmsg_enable; #define ZFS_DEBUG_DPRINTF (1 << 0) #define ZFS_DEBUG_DBUF_VERIFY (1 << 1) @@ -55,10 +56,22 @@ extern int zfs_free_leak_on_eio; extern void __dprintf(const char *file, const char *func, int line, const char *fmt, ...); -#define dprintf(...) \ - __dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__) #define zfs_dbgmsg(...) \ - __dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__) + if (zfs_dbgmsg_enable) \ + __dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__) + +#ifdef ZFS_DEBUG +/* + * To enable this: + * + * $ echo 1 >/sys/module/zfs/parameters/zfs_flags + */ +#define dprintf(...) \ + if (zfs_flags & ZFS_DEBUG_DPRINTF) \ + __dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__) +#else +#define dprintf(...) ((void)0) +#endif /* ZFS_DEBUG */ extern void zfs_panic_recover(const char *fmt, ...); diff --git a/module/zfs/arc.c b/module/zfs/arc.c index c6ff6171c..9c0c5513d 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -7138,6 +7138,7 @@ arc_tempreserve_space(uint64_t reserve, uint64_t txg) if (reserve + arc_tempreserve + anon_size > arc_c / 2 && anon_size > arc_c / 4) { +#ifdef ZFS_DEBUG uint64_t meta_esize = refcount_count(&arc_anon->arcs_esize[ARC_BUFC_METADATA]); uint64_t data_esize = @@ -7146,6 +7147,7 @@ arc_tempreserve_space(uint64_t reserve, uint64_t txg) "anon_data=%lluK tempreserve=%lluK arc_c=%lluK\n", arc_tempreserve >> 10, meta_esize >> 10, data_esize >> 10, reserve >> 10, arc_c >> 10); +#endif DMU_TX_STAT_BUMP(dmu_tx_dirty_throttle); return (SET_ERROR(ERESTART)); } diff --git a/module/zfs/dmu_send.c b/module/zfs/dmu_send.c index d39ab1a9e..36e412bdf 100644 --- a/module/zfs/dmu_send.c +++ b/module/zfs/dmu_send.c @@ -3440,6 +3440,7 @@ receive_read_record(struct receive_arg *ra) static void dprintf_drr(struct receive_record_arg *rrd, int err) { +#ifdef ZFS_DEBUG switch (rrd->header.drr_type) { case DRR_OBJECT: { @@ -3520,6 +3521,7 @@ dprintf_drr(struct receive_record_arg *rrd, int err) default: return; } +#endif } /* diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c index d71468db3..5e2af24e3 100644 --- a/module/zfs/spa_misc.c +++ b/module/zfs/spa_misc.c @@ -243,8 +243,7 @@ kmem_cache_t *spa_buffer_pool; int spa_mode_global; #ifdef ZFS_DEBUG -/* Everything except dprintf and spa is on by default in debug builds */ -int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SPA); +int zfs_flags = ~(ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SET_ERROR | ZFS_DEBUG_SPA); #else int zfs_flags = 0; #endif diff --git a/module/zfs/zfs_debug.c b/module/zfs/zfs_debug.c index d1dba3f8f..e2aff28e1 100644 --- a/module/zfs/zfs_debug.c +++ b/module/zfs/zfs_debug.c @@ -33,20 +33,18 @@ int zfs_dbgmsg_maxsize = 4<<20; /* 4MB */ kstat_t *zfs_dbgmsg_kstat; /* - * By default only enable the internal ZFS debug messages when running - * in userspace (ztest). The kernel log must be manually enabled. + * Internal ZFS debug messages are enabled by default. * - * # Enable the kernel debug message log. - * echo 1 > /sys/module/zfs/parameters/zfs_dbgmsg_enable + * # Print debug messages + * cat /proc/spl/kstat/zfs/dbgmsg + * + * # Disable the kernel debug message log. + * echo 0 > /sys/module/zfs/parameters/zfs_dbgmsg_enable * * # Clear the kernel debug message log. * echo 0 >/proc/spl/kstat/zfs/dbgmsg */ -#if defined(_KERNEL) && !defined(ZFS_DEBUG) -int zfs_dbgmsg_enable = 0; -#else int zfs_dbgmsg_enable = 1; -#endif static int zfs_dbgmsg_headers(char *buf, size_t size) @@ -164,6 +162,11 @@ __zfs_dbgmsg(char *buf) void __set_error(const char *file, const char *func, int line, int err) { + /* + * To enable this: + * + * $ echo 512 >/sys/module/zfs/parameters/zfs_flags + */ if (zfs_flags & ZFS_DEBUG_SET_ERROR) __dprintf(file, func, line, "error %lu", err); } @@ -179,10 +182,6 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...) char *nl; int i; - if (!zfs_dbgmsg_enable && - !(zfs_flags & (ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SET_ERROR))) - return; - size = 1024; buf = kmem_alloc(size, KM_SLEEP); @@ -215,28 +214,23 @@ __dprintf(const char *file, const char *func, int line, const char *fmt, ...) * To get this data enable the zfs__dprintf trace point as shown: * * # Enable zfs__dprintf tracepoint, clear the tracepoint ring buffer - * $ echo 1 > /sys/module/zfs/parameters/zfs_flags * $ echo 1 > /sys/kernel/debug/tracing/events/zfs/enable * $ echo 0 > /sys/kernel/debug/tracing/trace * * # Dump the ring buffer. * $ cat /sys/kernel/debug/tracing/trace */ - if (zfs_flags & (ZFS_DEBUG_DPRINTF | ZFS_DEBUG_SET_ERROR)) - DTRACE_PROBE1(zfs__dprintf, char *, buf); + DTRACE_PROBE1(zfs__dprintf, char *, buf); /* - * To get this data enable the zfs debug log as shown: + * To get this data: * - * # Set zfs_dbgmsg enable, clear the log buffer - * $ echo 1 > /sys/module/zfs/parameters/zfs_dbgmsg_enable - * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg - * - * # Dump the log buffer. * $ cat /proc/spl/kstat/zfs/dbgmsg + * + * To clear the buffer: + * $ echo 0 > /proc/spl/kstat/zfs/dbgmsg */ - if (zfs_dbgmsg_enable) - __zfs_dbgmsg(buf); + __zfs_dbgmsg(buf); kmem_free(buf, size); }