Date: Sun, 06 Oct 2019 21:19:24 -0700 From: Cy Schubert <Cy.Schubert@cschubert.com> To: Mateusz Guzik <mjg@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r353149 - head/sys/amd64/amd64 Message-ID: <201910070419.x974JOkQ020574@slippy.cwsent.com> In-Reply-To: <201910070406.x9746N0U009068@slippy.cwsent.com> References: <201910062213.x96MDZv3085523@repo.freebsd.org> <201910070406.x9746N0U009068@slippy.cwsent.com>
next in thread | previous in thread | raw e-mail | index | archive | help
In message <201910070406.x9746N0U009068@slippy.cwsent.com>, Cy Schubert writes: > In message <201910062213.x96MDZv3085523@repo.freebsd.org>, Mateusz Guzik > writes > : > > Author: mjg > > Date: Sun Oct 6 22:13:35 2019 > > New Revision: 353149 > > URL: https://svnweb.freebsd.org/changeset/base/353149 > > > > Log: > > amd64 pmap: implement per-superpage locks > > > > The current 256-lock sized array is a problem in the following ways: > > - it's way too small > > - there are 2 locks per cacheline > > - it is not NUMA-aware > > > > Solve these issues by introducing per-superpage locks backed by pages > > allocated from respective domains. > > > > This significantly reduces contention e.g. during poudriere -j 104. > > See the review for results. > > > > Reviewed by: kib > > Discussed with: jeff > > Sponsored by: The FreeBSD Foundation > > Differential Revision: https://reviews.freebsd.org/D21833 > > > > Modified: > > head/sys/amd64/amd64/pmap.c > > > > Modified: head/sys/amd64/amd64/pmap.c > > =========================================================================== > == > > = > > --- head/sys/amd64/amd64/pmap.c Sun Oct 6 20:36:25 2019 (r35314 > > 8) > > +++ head/sys/amd64/amd64/pmap.c Sun Oct 6 22:13:35 2019 (r35314 > > 9) > > @@ -316,13 +316,25 @@ pmap_pku_mask_bit(pmap_t pmap) > > #define PV_STAT(x) do { } while (0) > > #endif > > > > -#define pa_index(pa) ((pa) >> PDRSHIFT) > > +#undef pa_index > > +#define pa_index(pa) ({ \ > > + KASSERT((pa) <= vm_phys_segs[vm_phys_nsegs - 1].end, \ > > + ("address %lx beyond the last segment", (pa))); \ > > + (pa) >> PDRSHIFT; \ > > +}) > > +#if VM_NRESERVLEVEL > 0 > > +#define pa_to_pmdp(pa) (&pv_table[pa_index(pa)]) > > +#define pa_to_pvh(pa) (&(pa_to_pmdp(pa)->pv_page)) > > +#define PHYS_TO_PV_LIST_LOCK(pa) \ > > + (&(pa_to_pmdp(pa)->pv_lock)) > > +#else > > #define pa_to_pvh(pa) (&pv_table[pa_index(pa)]) > > > > #define NPV_LIST_LOCKS MAXCPU > > > > #define PHYS_TO_PV_LIST_LOCK(pa) \ > > (&pv_list_locks[pa_index(pa) % NPV_LIST_LOCKS]) > > +#endif > > > > #define CHANGE_PV_LIST_LOCK_TO_PHYS(lockp, pa) do { \ > > struct rwlock **_lockp = (lockp); \ > > @@ -400,14 +412,22 @@ static int pmap_initialized; > > > > /* > > * Data for the pv entry allocation mechanism. > > - * Updates to pv_invl_gen are protected by the pv_list_locks[] > > - * elements, but reads are not. > > + * Updates to pv_invl_gen are protected by the pv list lock but reads are > no > > t. > > */ > > static TAILQ_HEAD(pch, pv_chunk) pv_chunks = TAILQ_HEAD_INITIALIZER(pv_chu > nk > > s); > > static struct mtx __exclusive_cache_line pv_chunks_mutex; > > +#if VM_NRESERVLEVEL > 0 > > +struct pmap_large_md_page { > > + struct rwlock pv_lock; > > + struct md_page pv_page; > > + u_long pv_invl_gen; > > +}; > > +static struct pmap_large_md_page *pv_table; > > +#else > > static struct rwlock __exclusive_cache_line pv_list_locks[NPV_LIST_LOCKS]; > > static u_long pv_invl_gen[NPV_LIST_LOCKS]; > > static struct md_page *pv_table; > > +#endif > > static struct md_page pv_dummy; > > > > /* > > @@ -918,12 +938,21 @@ SYSCTL_LONG(_vm_pmap, OID_AUTO, invl_wait_slow, CTLFL > A > > "Number of slow invalidation waits for lockless DI"); > > #endif > > > > +#if VM_NRESERVLEVEL > 0 > > static u_long * > > pmap_delayed_invl_genp(vm_page_t m) > > { > > > > + return (&pa_to_pmdp(VM_PAGE_TO_PHYS(m))->pv_invl_gen); > > +} > > +#else > > +static u_long * > > +pmap_delayed_invl_genp(vm_page_t m) > > +{ > > + > > return (&pv_invl_gen[pa_index(VM_PAGE_TO_PHYS(m)) % NPV_LIST_LOCKS]); > > } > > +#endif > > > > static void > > pmap_delayed_invl_callout_func(void *arg __unused) > > @@ -1803,6 +1832,112 @@ pmap_page_init(vm_page_t m) > > m->md.pat_mode = PAT_WRITE_BACK; > > } > > > > +#if VM_NRESERVLEVEL > 0 > > +static void > > +pmap_init_pv_table(void) > > +{ > > + struct pmap_large_md_page *pvd; > > + vm_size_t s; > > + long start, end, highest, pv_npg; > > + int domain, i, j, pages; > > + > > + /* > > + * We strongly depend on the size being a power of two, so the assert > > + * is overzealous. However, should the struct be resized to a > > + * different power of two, the code below needs to be revisited. > > + */ > > + CTASSERT((sizeof(*pvd) == 64)); > > + > > + /* > > + * Calculate the size of the array. > > + */ > > + pv_npg = howmany(vm_phys_segs[vm_phys_nsegs - 1].end, NBPDR); > > + s = (vm_size_t)pv_npg * sizeof(struct pmap_large_md_page); > > + s = round_page(s); > > + pv_table = (struct pmap_large_md_page *)kva_alloc(s); > > + if (pv_table == NULL) > > + panic("%s: kva_alloc failed\n", __func__); > > + > > + /* > > + * Iterate physical segments to allocate space for respective pages. > > + */ > > + highest = -1; > > + s = 0; > > + for (i = 0; i < vm_phys_nsegs; i++) { > > + start = vm_phys_segs[i].start / NBPDR; > > + end = vm_phys_segs[i].end / NBPDR; > > + domain = vm_phys_segs[i].domain; > > + > > + if (highest >= end) > > + continue; > > + > > + if (start < highest) { > > + start = highest + 1; > > + pvd = &pv_table[start]; > > + } else { > > + /* > > + * The lowest address may land somewhere in the middle > > + * of our page. Simplify the code by pretending it is > > + * at the beginning. > > + */ > > + pvd = pa_to_pmdp(vm_phys_segs[i].start); > > + pvd = (struct pmap_large_md_page *)trunc_page(pvd); > > + start = pvd - pv_table; > > + } > > + > > + pages = end - start + 1; > > + s = round_page(pages * sizeof(*pvd)); > > + highest = start + (s / sizeof(*pvd)) - 1; > > + > > + for (j = 0; j < s; j += PAGE_SIZE) { > > + vm_page_t m = vm_page_alloc_domain(NULL, 0, > > + domain, VM_ALLOC_NORMAL | VM_ALLOC_NOOBJ); > > + if (m == NULL) > > + panic("vm_page_alloc_domain failed for %lx\n", > > (vm_offset_t)pvd + j); > > + pmap_qenter((vm_offset_t)pvd + j, &m, 1); > > + } > > + > > + for (j = 0; j < s / sizeof(*pvd); j++) { > > + rw_init_flags(&pvd->pv_lock, "pmap pv list", RW_NEW); > > + TAILQ_INIT(&pvd->pv_page.pv_list); > > + pvd->pv_page.pv_gen = 0; > > + pvd->pv_page.pat_mode = 0; > > + pvd->pv_invl_gen = 0; > > + pvd++; > > + } > > + } > > + TAILQ_INIT(&pv_dummy.pv_list); > > +} > > +#else > > +static void > > +pmap_init_pv_table(void) > > +{ > > + vm_size_t s; > > + long i, pv_npg; > > + > > + /* > > + * Initialize the pool of pv list locks. > > + */ > > + for (i = 0; i < NPV_LIST_LOCKS; i++) > > + rw_init(&pv_list_locks[i], "pmap pv list"); > > + > > + /* > > + * Calculate the size of the pv head table for superpages. > > + */ > > + pv_npg = howmany(vm_phys_segs[vm_phys_nsegs - 1].end, NBPDR); > > + > > + /* > > + * Allocate memory for the pv head table for superpages. > > + */ > > + s = (vm_size_t)pv_npg * sizeof(struct md_page); > > + s = round_page(s); > > + pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO); > > + for (i = 0; i < pv_npg; i++) > > + TAILQ_INIT(&pv_table[i].pv_list); > > + TAILQ_INIT(&pv_dummy.pv_list); > > +} > > +#endif > > + > > /* > > * Initialize the pmap module. > > * Called by vm_init, to initialize any structures that the pmap > > @@ -1813,8 +1948,7 @@ pmap_init(void) > > { > > struct pmap_preinit_mapping *ppim; > > vm_page_t m, mpte; > > - vm_size_t s; > > - int error, i, pv_npg, ret, skz63; > > + int error, i, ret, skz63; > > > > /* L1TF, reserve page @0 unconditionally */ > > vm_page_blacklist_add(0, bootverbose); > > @@ -1902,26 +2036,7 @@ pmap_init(void) > > */ > > mtx_init(&pv_chunks_mutex, "pmap pv chunk list", NULL, MTX_DEF); > > > > - /* > > - * Initialize the pool of pv list locks. > > - */ > > - for (i = 0; i < NPV_LIST_LOCKS; i++) > > - rw_init(&pv_list_locks[i], "pmap pv list"); > > - > > - /* > > - * Calculate the size of the pv head table for superpages. > > - */ > > - pv_npg = howmany(vm_phys_segs[vm_phys_nsegs - 1].end, NBPDR); > > - > > - /* > > - * Allocate memory for the pv head table for superpages. > > - */ > > - s = (vm_size_t)(pv_npg * sizeof(struct md_page)); > > - s = round_page(s); > > - pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO); > > - for (i = 0; i < pv_npg; i++) > > - TAILQ_INIT(&pv_table[i].pv_list); > > - TAILQ_INIT(&pv_dummy.pv_list); > > + pmap_init_pv_table(); > > > > pmap_initialized = 1; > > for (i = 0; i < PMAP_PREINIT_MAPPING_COUNT; i++) { > > > > This causes a page fault during X (xdm) startup, which loads > drm-current-kmod. > > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > 0xfffffe0093e9c260 > vpanic() at vpanic+0x19d/frame 0xfffffe0093e9c2b0 > panic() at panic+0x43/frame 0xfffffe0093e9c310 > vm_fault() at vm_fault+0x2126/frame 0xfffffe0093e9c460 > vm_fault_trap() at vm_fault_trap+0x73/frame 0xfffffe0093e9c4b0 > trap_pfault() at trap_pfault+0x1b6/frame 0xfffffe0093e9c510 > trap() at trap+0x2a1/frame 0xfffffe0093e9c620 > calltrap() at calltrap+0x8/frame 0xfffffe0093e9c620 > --- trap 0xc, rip = 0xffffffff80a054b1, rsp = 0xfffffe0093e9c6f0, rbp = > 0xfffffe0093e9c7a0 --- > pmap_enter() at pmap_enter+0x861/frame 0xfffffe0093e9c7a0 > vm_fault() at vm_fault+0x1c69/frame 0xfffffe0093e9c8f0 > vm_fault_trap() at vm_fault_trap+0x73/frame 0xfffffe0093e9c940 > trap_pfault() at trap_pfault+0x1b6/frame 0xfffffe0093e9c9a0 > trap() at trap+0x438/frame 0xfffffe0093e9cab0 > calltrap() at calltrap+0x8/frame 0xfffffe0093e9cab0 > --- trap 0xc, rip = 0x30e2a9c3, rsp = 0x7fffffffea50, rbp = 0x7fffffffeaa0 > --- > Uptime: 3m33s > Dumping 945 out of 7974 MB:..2%..11%..21%..31%..41%..51%..61%..72%..82%..92% > > (kgdb) bt > #0 doadump (textdump=1) at pcpu_aux.h:55 > #1 0xffffffff8068c5ed in kern_reboot (howto=260) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:479 > #2 0xffffffff8068caa9 in vpanic (fmt=<value optimized out>, > ap=<value optimized out>) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:908 > #3 0xffffffff8068c8a3 in panic (fmt=<value optimized out>) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:835 > #4 0xffffffff8098c966 in vm_fault (map=<value optimized out>, > vaddr=<value optimized out>, fault_type=<value optimized out>, > fault_flags=<value optimized out>, m_hold=<value optimized out>) > at /opt/src/svn-current/sys/vm/vm_fault.c:672 > #5 0xffffffff8098a723 in vm_fault_trap (map=0xfffff80002001000, > vaddr=<value optimized out>, fault_type=2 '\002', > fault_flags=<value optimized out>, signo=0x0, ucode=0x0) > at /opt/src/svn-current/sys/vm/vm_fault.c:568 > #6 0xffffffff80a18326 in trap_pfault (frame=0xfffffe0093e9c630, > signo=<value optimized out>, ucode=<value optimized out>) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:828 > #7 0xffffffff80a177f1 in trap (frame=0xfffffe0093e9c630) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:407 > #8 0xffffffff809f1aac in calltrap () > at /opt/src/svn-current/sys/amd64/amd64/exception.S:289 > ---Type <return> to continue, or q <return> to quit--- > #9 0xffffffff80a054b1 in pmap_enter (pmap=<value optimized out>, > va=851443712, m=0xfffffe0005b25ce8, prot=<value optimized out>, > flags=2677542912, psind=<value optimized out>) at atomic.h:221 > #10 0xffffffff8098c4a9 in vm_fault (map=<value optimized out>, > vaddr=<value optimized out>, fault_type=232 '\ufffd', > fault_flags=<value optimized out>, m_hold=0x0) > at /opt/src/svn-current/sys/vm/vm_fault.c:489 > #11 0xffffffff8098a723 in vm_fault_trap (map=0xfffff80173eb5000, > vaddr=<value optimized out>, fault_type=2 '\002', > fault_flags=<value optimized out>, signo=0xfffffe0093e9ca84, > ucode=0xfffffe0093e9ca80) at /opt/src/svn-current/sys/vm/vm_fault.c:568 > #12 0xffffffff80a18326 in trap_pfault (frame=0xfffffe0093e9cac0, > signo=<value optimized out>, ucode=<value optimized out>) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:828 > #13 0xffffffff80a17988 in trap (frame=0xfffffe0093e9cac0) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:347 > #14 0xffffffff809f1aac in calltrap () > at /opt/src/svn-current/sys/amd64/amd64/exception.S:289 > #15 0x0000000030e2a9c3 in ?? () > Previous frame inner to this frame (corrupt stack?) > Current language: auto; currently minimal > (kgdb) frame 9 > #9 0xffffffff80a054b1 in pmap_enter (pmap=<value optimized out>, > va=851443712, m=0xfffffe0005b25ce8, prot=<value optimized out>, > flags=2677542912, psind=<value optimized out>) at atomic.h:221 > 221 ATOMIC_CMPSET(long); > (kgdb) l > 216 } > 217 > 218 ATOMIC_CMPSET(char); > 219 ATOMIC_CMPSET(short); > 220 ATOMIC_CMPSET(int); > 221 ATOMIC_CMPSET(long); > 222 > 223 /* > 224 * Atomically add the value of v to the integer pointed to by p and > return > 225 * the previous value of *p. > (kgdb) I should use kgdb from ports instead of /usr/libexec version. Similar result. <4>WARN_ON(!mutex_is_locked(&fbc->lock))WARN_ON(!mutex_is_locked(&fbc-> lock)) panic: vm_fault: fault on nofault entry, addr: 0xfffffe000e01c000 cpuid = 1 time = 1570417211 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0093e9c260 vpanic() at vpanic+0x19d/frame 0xfffffe0093e9c2b0 panic() at panic+0x43/frame 0xfffffe0093e9c310 vm_fault() at vm_fault+0x2126/frame 0xfffffe0093e9c460 vm_fault_trap() at vm_fault_trap+0x73/frame 0xfffffe0093e9c4b0 trap_pfault() at trap_pfault+0x1b6/frame 0xfffffe0093e9c510 trap() at trap+0x2a1/frame 0xfffffe0093e9c620 calltrap() at calltrap+0x8/frame 0xfffffe0093e9c620 --- trap 0xc, rip = 0xffffffff80a054b1, rsp = 0xfffffe0093e9c6f0, rbp = 0xfffffe0093e9c7a0 --- pmap_enter() at pmap_enter+0x861/frame 0xfffffe0093e9c7a0 vm_fault() at vm_fault+0x1c69/frame 0xfffffe0093e9c8f0 vm_fault_trap() at vm_fault_trap+0x73/frame 0xfffffe0093e9c940 trap_pfault() at trap_pfault+0x1b6/frame 0xfffffe0093e9c9a0 trap() at trap+0x438/frame 0xfffffe0093e9cab0 calltrap() at calltrap+0x8/frame 0xfffffe0093e9cab0 --- trap 0xc, rip = 0x30e2a9c3, rsp = 0x7fffffffea50, rbp = 0x7fffffffeaa0 --- Uptime: 3m33s Dumping 945 out of 7974 MB:..2%..11%..21%..31%..41%..51%..61%..72%..82%..92% __curthread () at /opt/src/svn-current/sys/amd64/include/pcpu_aux.h:55 55 __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" (offsetof(struct pcpu, (kgdb) Backtrace stopped: Cannot access memory at address 0x7fffffffea50 (kgdb) frame 10 #10 0xffffffff80a054b1 in atomic_fcmpset_long (dst=<optimized out>, src=<optimized out>, expect=<optimized out>) at /opt/src/svn-current/sys/amd64/include/atomic.h:221 221 ATOMIC_CMPSET(long); (kgdb) l 216 } 217 218 ATOMIC_CMPSET(char); 219 ATOMIC_CMPSET(short); 220 ATOMIC_CMPSET(int); 221 ATOMIC_CMPSET(long); 222 223 /* 224 * Atomically add the value of v to the integer pointed to by p and return 225 * the previous value of *p. (kgdb) -- Cheers, Cy Schubert <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201910070419.x974JOkQ020574>