From 91b2f6ab1cd6c105eae00d6e046d58eb7ab271db Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Tue, 10 Oct 2017 15:19:19 -0700 Subject: [PATCH] Fix ARC behavior on 32-bit systems With the addition of the ABD changes consumption of the virtual address space has been greatly reduced. This exposed an issue on CONFIG_HIGHMEM systems where free memory was being calculated incorrectly. Functionally this didn't cause any major problems prior to ABD because a lack of available virtual address space was used as an indicator of low memory. This patch makes the following changes to address the issue and in the process realigns the code further with OpenZFS. There are no substantive changes in behavior for 64-bit systems. * Added CONFIG_HIGHMEM case to the arc_all_memory() and arc_free_memory() functions to only consider low memory pages on CONFIG_HIGHMEM systems. * The arc_free_memory() function was updated to return bytes instead of pages to be consistent with the other helper functions. In user space we make up some reasonable values since currently only testing is performed in this context. * Adds three new values to the arcstats kstat to provide visibility in to the ARC's assessment of the memory situation: memory_all_bytes, memory_free_bytes, and memory_available_bytes. * Added kmem_reap() call to arc_available_memory() for 32-bit builds to realign code with OpenZFS. * Reduced size of test file in /async_destroy_001_pos.ksh to speed up test case. Multiple txgs are still required. * Move vdevs used by zpool_clear_001_pos and zpool_upgrade_002_pos to TEST_BASE_DIR location to speed up test cases. Reviewed-by: David Quigley Signed-off-by: Brian Behlendorf Closes #5352 Closes #6734 --- module/zfs/arc.c | 85 +++++++++++++------ .../zpool_clear/zpool_clear_001_pos.ksh | 6 +- .../zpool_upgrade/zpool_upgrade.kshlib | 10 +-- .../zpool_upgrade/zpool_upgrade_004_pos.ksh | 8 +- .../async_destroy/async_destroy_001_pos.ksh | 9 +- 5 files changed, 73 insertions(+), 45 deletions(-) diff --git a/module/zfs/arc.c b/module/zfs/arc.c index d678b335c..48950245e 100644 --- a/module/zfs/arc.c +++ b/module/zfs/arc.c @@ -632,6 +632,9 @@ typedef struct arc_stats { kstat_named_t arcstat_memory_throttle_count; kstat_named_t arcstat_memory_direct_count; kstat_named_t arcstat_memory_indirect_count; + kstat_named_t arcstat_memory_all_bytes; + kstat_named_t arcstat_memory_free_bytes; + kstat_named_t arcstat_memory_available_bytes; kstat_named_t arcstat_no_grow; kstat_named_t arcstat_tempreserve; kstat_named_t arcstat_loaned_bytes; @@ -727,6 +730,9 @@ static arc_stats_t arc_stats = { { "memory_throttle_count", KSTAT_DATA_UINT64 }, { "memory_direct_count", KSTAT_DATA_UINT64 }, { "memory_indirect_count", KSTAT_DATA_UINT64 }, + { "memory_all_bytes", KSTAT_DATA_UINT64 }, + { "memory_free_bytes", KSTAT_DATA_UINT64 }, + { "memory_available_bytes", KSTAT_DATA_INT64 }, { "arc_no_grow", KSTAT_DATA_UINT64 }, { "arc_tempreserve", KSTAT_DATA_UINT64 }, { "arc_loaned_bytes", KSTAT_DATA_UINT64 }, @@ -3981,30 +3987,46 @@ static uint64_t arc_all_memory(void) { #ifdef _KERNEL - return (MIN(ptob(physmem), - vmem_size(heap_arena, VMEM_FREE | VMEM_ALLOC))); +#ifdef CONFIG_HIGHMEM + return (ptob(totalram_pages - totalhigh_pages)); +#else + return (ptob(totalram_pages)); +#endif /* CONFIG_HIGHMEM */ #else return (ptob(physmem) / 2); -#endif +#endif /* _KERNEL */ } -#ifdef _KERNEL +/* + * Return the amount of memory that is considered free. In user space + * which is primarily used for testing we pretend that free memory ranges + * from 0-20% of all memory. + */ static uint64_t arc_free_memory(void) { +#ifdef _KERNEL +#ifdef CONFIG_HIGHMEM + struct sysinfo si; + si_meminfo(&si); + return (ptob(si.freeram - si.freehigh)); +#else #ifdef ZFS_GLOBAL_NODE_PAGE_STATE - return (nr_free_pages() + + return (ptob(nr_free_pages() + global_node_page_state(NR_INACTIVE_FILE) + global_node_page_state(NR_INACTIVE_ANON) + - global_node_page_state(NR_SLAB_RECLAIMABLE)); + global_node_page_state(NR_SLAB_RECLAIMABLE))); #else - return (nr_free_pages() + + return (ptob(nr_free_pages() + global_page_state(NR_INACTIVE_FILE) + global_page_state(NR_INACTIVE_ANON) + - global_page_state(NR_SLAB_RECLAIMABLE)); -#endif + global_page_state(NR_SLAB_RECLAIMABLE))); +#endif /* ZFS_GLOBAL_NODE_PAGE_STATE */ +#endif /* CONFIG_HIGHMEM */ +#else + return (spa_get_random(arc_all_memory() * 20 / 100)); +#endif /* _KERNEL */ } -#endif typedef enum free_memory_reason_t { FMR_UNKNOWN, @@ -4042,17 +4064,15 @@ arc_available_memory(void) int64_t lowest = INT64_MAX; free_memory_reason_t r = FMR_UNKNOWN; #ifdef _KERNEL - uint64_t available_memory = ptob(arc_free_memory()); int64_t n; #ifdef __linux__ +#ifdef freemem +#undef freemem +#endif pgcnt_t needfree = btop(arc_need_free); pgcnt_t lotsfree = btop(arc_sys_free); pgcnt_t desfree = 0; -#endif - -#if defined(__i386) - available_memory = - MIN(available_memory, vmem_size(heap_arena, VMEM_FREE)); + pgcnt_t freemem = btop(arc_free_memory()); #endif if (needfree > 0) { @@ -4070,7 +4090,7 @@ arc_available_memory(void) * number of needed free pages. We add extra pages here to make sure * the scanner doesn't start up while we're freeing memory. */ - n = PAGESIZE * (btop(available_memory) - lotsfree - needfree - desfree); + n = PAGESIZE * (freemem - lotsfree - needfree - desfree); if (n < lowest) { lowest = n; r = FMR_LOTSFREE; @@ -4091,7 +4111,6 @@ arc_available_memory(void) r = FMR_SWAPFS_MINFREE; } - /* * Check that we have enough availrmem that memory locking (e.g., via * mlock(3C) or memcntl(2)) can still succeed. (pages_pp_maximum @@ -4107,9 +4126,9 @@ arc_available_memory(void) } #endif -#if defined(__i386) +#if defined(_ILP32) /* - * If we're on an i386 platform, it's possible that we'll exhaust the + * If we're on a 32-bit platform, it's possible that we'll exhaust the * kernel heap space before we ever run out of available physical * memory. Most checks of the size of the heap_area compare against * tune.t_minarmem, which is the minimum available real memory that we @@ -4178,6 +4197,7 @@ arc_kmem_reap_now(void) extern kmem_cache_t *zio_data_buf_cache[]; extern kmem_cache_t *range_seg_cache; +#ifdef _KERNEL if ((arc_meta_used >= arc_meta_limit) && zfs_arc_meta_prune) { /* * We are exceeding our meta-data cache limit. @@ -4185,9 +4205,16 @@ arc_kmem_reap_now(void) */ arc_prune_async(zfs_arc_meta_prune); } +#if defined(_ILP32) + /* + * Reclaim unused memory from all kmem caches. + */ + kmem_reap(); +#endif +#endif for (i = 0; i < SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT; i++) { -#ifdef _ILP32 +#if defined(_ILP32) /* reach upper limit of cache size on 32-bit */ if (zio_buf_cache[i] == NULL) break; @@ -6077,14 +6104,11 @@ static int arc_memory_throttle(uint64_t reserve, uint64_t txg) { #ifdef _KERNEL - uint64_t available_memory = ptob(arc_free_memory()); + uint64_t available_memory = arc_free_memory(); static uint64_t page_load = 0; static uint64_t last_txg = 0; -#ifdef __linux__ - pgcnt_t minfree = btop(arc_sys_free / 4); -#endif -#if defined(__i386) +#if defined(_ILP32) available_memory = MIN(available_memory, vmem_size(heap_arena, VMEM_FREE)); #endif @@ -6102,7 +6126,7 @@ arc_memory_throttle(uint64_t reserve, uint64_t txg) * continue to let page writes occur as quickly as possible. */ if (current_is_kswapd()) { - if (page_load > MAX(ptob(minfree), available_memory) / 4) { + if (page_load > MAX(arc_sys_free / 4, available_memory) / 4) { DMU_TX_STAT_BUMP(dmu_tx_memory_reclaim); return (SET_ERROR(ERESTART)); } @@ -6232,6 +6256,13 @@ arc_kstat_update(kstat_t *ksp, int rw) &as->arcstat_mfu_ghost_size, &as->arcstat_mfu_ghost_evictable_data, &as->arcstat_mfu_ghost_evictable_metadata); + + as->arcstat_memory_all_bytes.value.ui64 = + arc_all_memory(); + as->arcstat_memory_free_bytes.value.ui64 = + arc_free_memory(); + as->arcstat_memory_available_bytes.value.i64 = + arc_available_memory(); } return (0); diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_clear/zpool_clear_001_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_clear/zpool_clear_001_pos.ksh index d537ecc56..e53481932 100755 --- a/tests/zfs-tests/tests/functional/cli_root/zpool_clear/zpool_clear_001_pos.ksh +++ b/tests/zfs-tests/tests/functional/cli_root/zpool_clear/zpool_clear_001_pos.ksh @@ -50,7 +50,7 @@ function cleanup poolexists $TESTPOOL1 && \ log_must zpool destroy -f $TESTPOOL1 - for file in `ls $TESTDIR/file.*`; do + for file in `ls $TEST_BASE_DIR/file.*`; do log_must rm -f $file done } @@ -62,12 +62,12 @@ log_onexit cleanup #make raw files to create various configuration pools typeset -i i=0 while (( i < 3 )); do - log_must mkfile $FILESIZE $TESTDIR/file.$i + log_must truncate -s $FILESIZE $TEST_BASE_DIR/file.$i (( i = i + 1 )) done -fbase=$TESTDIR/file +fbase=$TEST_BASE_DIR/file set -A poolconf "mirror $fbase.0 $fbase.1 $fbase.2" \ "raidz1 $fbase.0 $fbase.1 $fbase.2" \ "raidz2 $fbase.0 $fbase.1 $fbase.2" diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade.kshlib b/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade.kshlib index 51986e6c2..d4d229cc9 100644 --- a/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade.kshlib +++ b/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade.kshlib @@ -50,9 +50,9 @@ function create_old_pool for pool_file in $pool_files; do log_must bzcat \ $STF_SUITE/tests/functional/cli_root/zpool_upgrade/$pool_file.bz2 \ - >/$TESTPOOL/$pool_file + >$TEST_BASE_DIR/$pool_file done - log_must zpool import -d /$TESTPOOL $pool_name + log_must zpool import -d $TEST_BASE_DIR $pool_name # Put some random contents into the pool for i in {1..1024} ; do @@ -97,7 +97,7 @@ function destroy_upgraded_pool log_must zpool destroy $pool_name fi for file in $pool_files; do - rm -f /$TESTPOOL/$file + rm -f $TEST_BASE_DIR/$file done } @@ -112,8 +112,8 @@ function check_pool typeset pool=$1 typeset flag=$2 find /$pool -type f -exec cksum {} + > \ - /$TESTPOOL/pool-checksums.$pool.$flag - echo /$TESTPOOL/pool-checksums.$pool.$flag + $TEST_BASE_DIR/pool-checksums.$pool.$flag + echo $TEST_BASE_DIR/pool-checksums.$pool.$flag } # This function simply checks that a pool has a particular version number diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade_004_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade_004_pos.ksh index 97325e9b1..241cd2d80 100755 --- a/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade_004_pos.ksh +++ b/tests/zfs-tests/tests/functional/cli_root/zpool_upgrade/zpool_upgrade_004_pos.ksh @@ -78,10 +78,10 @@ for config in $CONFIGS ; do typeset -n pool_name=ZPOOL_VERSION_${config}_NAME check_pool $pool_name post > /dev/null - log_must diff /$TESTPOOL/pool-checksums.$pool_name.pre \ - /$TESTPOOL/pool-checksums.$pool_name.post - rm /$TESTPOOL/pool-checksums.$pool_name.pre \ - /$TESTPOOL/pool-checksums.$pool_name.post + log_must diff $TEST_BASE_DIR/pool-checksums.$pool_name.pre \ + $TEST_BASE_DIR/pool-checksums.$pool_name.post + rm $TEST_BASE_DIR/pool-checksums.$pool_name.pre \ + $TEST_BASE_DIR/pool-checksums.$pool_name.post destroy_upgraded_pool $config done diff --git a/tests/zfs-tests/tests/functional/features/async_destroy/async_destroy_001_pos.ksh b/tests/zfs-tests/tests/functional/features/async_destroy/async_destroy_001_pos.ksh index 7258e635b..a6ef964ac 100755 --- a/tests/zfs-tests/tests/functional/features/async_destroy/async_destroy_001_pos.ksh +++ b/tests/zfs-tests/tests/functional/features/async_destroy/async_destroy_001_pos.ksh @@ -56,12 +56,9 @@ log_assert "async_destroy can suspend and resume traversal" log_must zfs create -o recordsize=512 -o compression=off $TEST_FS -# Create enough blocks that it will take 4 TXGs to free them all. -typeset zfs_free_max_blocks=100000 -typeset blocks=$((zfs_free_max_blocks * 4 * 512 / 1024 / 1024)) - -log_must dd bs=1024k count=$blocks if=/dev/zero of=/$TEST_FS/file - +# Create enough blocks that it will take multiple TXGs to free them all. +log_must dd bs=1024k count=128 if=/dev/zero of=/$TEST_FS/file +log_must sync log_must zfs destroy $TEST_FS # -- 2.40.0