Author: rlibby Date: Fri Dec 13 09:31:59 2019 New Revision: 355706 URL: https://svnweb.freebsd.org/changeset/base/355706
Log: uma dbg: flexible size for slab debug bitset too Recently (r355315) the size of the struct uma_slab bitset field us_free became dynamic instead of conservative. Now, make the debug bitset size dynamic too. The debug bitset is INVARIANTS-only, so in fact we don't care too much about the space savings that results from this, but enabling minimally-sized slabs on INVARIANTS builds is still important in order to be able to test new slab layouts effectively. Reviewed by: jeff, markj Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D22759 Modified: head/sys/vm/uma_core.c head/sys/vm/uma_int.h Modified: head/sys/vm/uma_core.c ============================================================================== --- head/sys/vm/uma_core.c Fri Dec 13 09:28:44 2019 (r355705) +++ head/sys/vm/uma_core.c Fri Dec 13 09:31:59 2019 (r355706) @@ -292,6 +292,8 @@ static int sysctl_handle_uma_zone_frees(SYSCTL_HANDLER static int sysctl_handle_uma_zone_flags(SYSCTL_HANDLER_ARGS); #ifdef INVARIANTS +static inline struct noslabbits *slab_dbg_bits(uma_slab_t slab, uma_keg_t keg); + static bool uma_dbg_kskip(uma_keg_t keg, void *mem); static bool uma_dbg_zskip(uma_zone_t zone, void *mem); static void uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *item); @@ -1201,7 +1203,7 @@ keg_alloc_slab(uma_keg_t keg, uma_zone_t zone, int dom slab->us_domain = domain; BIT_FILL(keg->uk_ipers, &slab->us_free); #ifdef INVARIANTS - BIT_ZERO(SLAB_MAX_SETSIZE, &slab->us_debugfree); + BIT_ZERO(keg->uk_ipers, slab_dbg_bits(slab, keg)); #endif if (keg->uk_init != NULL) { @@ -1484,6 +1486,15 @@ zero_init(void *mem, int size, int flags) return (0); } +#ifdef INVARIANTS +struct noslabbits * +slab_dbg_bits(uma_slab_t slab, uma_keg_t keg) +{ + + return ((void *)((char *)&slab->us_free + BITSET_SIZE(keg->uk_ipers))); +} +#endif + /* * Actual size of embedded struct slab (!OFFPAGE). */ @@ -1492,7 +1503,7 @@ slab_sizeof(int nitems) { size_t s; - s = sizeof(struct uma_slab) + BITSET_SIZE(nitems); + s = sizeof(struct uma_slab) + BITSET_SIZE(nitems) * SLAB_BITSETS; return (roundup(s, UMA_ALIGN_PTR + 1)); } @@ -4514,12 +4525,10 @@ uma_dbg_alloc(uma_zone_t zone, uma_slab_t slab, void * keg = zone->uz_keg; freei = slab_item_index(slab, keg, item); - if (BIT_ISSET(SLAB_MAX_SETSIZE, freei, &slab->us_debugfree)) + if (BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg))) panic("Duplicate alloc of %p from zone %p(%s) slab %p(%d)\n", item, zone, zone->uz_name, slab, freei); - BIT_SET_ATOMIC(SLAB_MAX_SETSIZE, freei, &slab->us_debugfree); - - return; + BIT_SET_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)); } /* @@ -4550,11 +4559,11 @@ uma_dbg_free(uma_zone_t zone, uma_slab_t slab, void *i panic("Unaligned free of %p from zone %p(%s) slab %p(%d)\n", item, zone, zone->uz_name, slab, freei); - if (!BIT_ISSET(SLAB_MAX_SETSIZE, freei, &slab->us_debugfree)) + if (!BIT_ISSET(keg->uk_ipers, freei, slab_dbg_bits(slab, keg))) panic("Duplicate free of %p from zone %p(%s) slab %p(%d)\n", item, zone, zone->uz_name, slab, freei); - BIT_CLR_ATOMIC(SLAB_MAX_SETSIZE, freei, &slab->us_debugfree); + BIT_CLR_ATOMIC(keg->uk_ipers, freei, slab_dbg_bits(slab, keg)); } #endif /* INVARIANTS */ Modified: head/sys/vm/uma_int.h ============================================================================== --- head/sys/vm/uma_int.h Fri Dec 13 09:28:44 2019 (r355705) +++ head/sys/vm/uma_int.h Fri Dec 13 09:31:59 2019 (r355706) @@ -271,17 +271,26 @@ struct uma_slab { uint16_t us_freecount; /* How many are free? */ uint8_t us_flags; /* Page flags see uma.h */ uint8_t us_domain; /* Backing NUMA domain. */ -#ifdef INVARIANTS - struct slabbits us_debugfree; /* Debug bitmask. */ -#endif - struct noslabbits us_free; /* Free bitmask. */ + struct noslabbits us_free; /* Free bitmask, flexible. */ }; +_Static_assert(sizeof(struct uma_slab) == offsetof(struct uma_slab, us_free), + "us_free field must be last"); #if MAXMEMDOM >= 255 #error "Slab domain type insufficient" #endif typedef struct uma_slab * uma_slab_t; +/* + * On INVARIANTS builds, the slab contains a second bitset of the same size, + * "dbg_bits", which is laid out immediately after us_free. + */ +#ifdef INVARIANTS +#define SLAB_BITSETS 2 +#else +#define SLAB_BITSETS 1 +#endif + /* These three functions are for embedded (!OFFPAGE) use only. */ size_t slab_sizeof(int nitems); size_t slab_space(int nitems); @@ -293,7 +302,10 @@ int slab_ipers(size_t size, int align); */ struct uma_hash_slab { struct uma_slab uhs_slab; /* Must be first. */ - struct slabbits uhs_bits; /* Must be second. */ + struct slabbits uhs_bits1; /* Must be second. */ +#ifdef INVARIANTS + struct slabbits uhs_bits2; /* Must be third. */ +#endif LIST_ENTRY(uma_hash_slab) uhs_hlink; /* Link for hash table */ uint8_t *uhs_data; /* First item */ }; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
