Date: Fri, 7 Jun 2019 06:35:42 +0000 (UTC) From: Andriy Gapon <avg@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348772 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <201906070635.x576ZgEE027350@repo.freebsd.org>
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Author: avg Date: Fri Jun 7 06:35:42 2019 New Revision: 348772 URL: https://svnweb.freebsd.org/changeset/base/348772 Log: Restore ARC MFU/MRU pressure Before r305323 (MFV r302991: 6950 ARC should cache compressed data) arc_read() code did this for access to a ghost buffer: arc_adapt() (from arc_get_data_buf()) arc_access(hdr, hash_lock) I.e., we first checked access to the MFU ghost/MRU ghost buffer and adapt MFU/MRU sizes (in arc_adapt()) and next move buffer from the ghost state to regular. After r305323 the sequence is different: arc_access(hdr, hash_lock); arc_hdr_alloc_pabd(hdr); I.e., we first move the buffer from the ghost state in arc_access() and then we check access to buffer in ghost state (in arc_hdr_alloc_pabd() -> arc_get_data_abd() -> arc_get_data_impl() -> arc_adapt()). This is incorrect: arc_adapt() never see access to the ghost buffer because arc_access() already migrated the buffer from the ghost state to regular. So, the fix is to restore a call to arc_adapt() before arc_access() and to suppress the call to arc_adapt() after arc_access(). Submitted by: Slawa Olhovchenkov <slw@zxy.spb.ru> MFC after: 2 weeks Sponsored by: Integros [integros.com] Differential Revision: https://reviews.freebsd.org/D19094 Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 7 05:03:03 2019 (r348771) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c Fri Jun 7 06:35:42 2019 (r348772) @@ -1560,14 +1560,14 @@ static kmutex_t l2arc_feed_thr_lock; static kcondvar_t l2arc_feed_thr_cv; static uint8_t l2arc_thread_exit; -static abd_t *arc_get_data_abd(arc_buf_hdr_t *, uint64_t, void *); +static abd_t *arc_get_data_abd(arc_buf_hdr_t *, uint64_t, void *, boolean_t); static void *arc_get_data_buf(arc_buf_hdr_t *, uint64_t, void *); -static void arc_get_data_impl(arc_buf_hdr_t *, uint64_t, void *); +static void arc_get_data_impl(arc_buf_hdr_t *, uint64_t, void *, boolean_t); static void arc_free_data_abd(arc_buf_hdr_t *, abd_t *, uint64_t, void *); static void arc_free_data_buf(arc_buf_hdr_t *, void *, uint64_t, void *); static void arc_free_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag); static void arc_hdr_free_pabd(arc_buf_hdr_t *); -static void arc_hdr_alloc_pabd(arc_buf_hdr_t *); +static void arc_hdr_alloc_pabd(arc_buf_hdr_t *, boolean_t); static void arc_access(arc_buf_hdr_t *, kmutex_t *); static boolean_t arc_is_overflowing(); static void arc_buf_watch(arc_buf_t *); @@ -3353,14 +3353,14 @@ arc_buf_destroy_impl(arc_buf_t *buf) } static void -arc_hdr_alloc_pabd(arc_buf_hdr_t *hdr) +arc_hdr_alloc_pabd(arc_buf_hdr_t *hdr, boolean_t do_adapt) { ASSERT3U(HDR_GET_LSIZE(hdr), >, 0); ASSERT(HDR_HAS_L1HDR(hdr)); ASSERT(!HDR_SHARED_DATA(hdr)); ASSERT3P(hdr->b_l1hdr.b_pabd, ==, NULL); - hdr->b_l1hdr.b_pabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr); + hdr->b_l1hdr.b_pabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr, do_adapt); hdr->b_l1hdr.b_byteswap = DMU_BSWAP_NUMFUNCS; ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); @@ -3424,7 +3424,7 @@ arc_hdr_alloc(uint64_t spa, int32_t psize, int32_t lsi * the compressed or uncompressed data depending on the block * it references and compressed arc enablement. */ - arc_hdr_alloc_pabd(hdr); + arc_hdr_alloc_pabd(hdr, B_TRUE); ASSERT(refcount_is_zero(&hdr->b_l1hdr.b_refcnt)); return (hdr); @@ -5145,11 +5145,11 @@ arc_is_overflowing(void) } static abd_t * -arc_get_data_abd(arc_buf_hdr_t *hdr, uint64_t size, void *tag) +arc_get_data_abd(arc_buf_hdr_t *hdr, uint64_t size, void *tag, boolean_t do_adapt) { arc_buf_contents_t type = arc_buf_type(hdr); - arc_get_data_impl(hdr, size, tag); + arc_get_data_impl(hdr, size, tag, do_adapt); if (type == ARC_BUFC_METADATA) { return (abd_alloc(size, B_TRUE)); } else { @@ -5163,7 +5163,7 @@ arc_get_data_buf(arc_buf_hdr_t *hdr, uint64_t size, vo { arc_buf_contents_t type = arc_buf_type(hdr); - arc_get_data_impl(hdr, size, tag); + arc_get_data_impl(hdr, size, tag, B_TRUE); if (type == ARC_BUFC_METADATA) { return (zio_buf_alloc(size)); } else { @@ -5179,12 +5179,13 @@ arc_get_data_buf(arc_buf_hdr_t *hdr, uint64_t size, vo * limit, we'll only signal the reclaim thread and continue on. */ static void -arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag) +arc_get_data_impl(arc_buf_hdr_t *hdr, uint64_t size, void *tag, boolean_t do_adapt) { arc_state_t *state = hdr->b_l1hdr.b_state; arc_buf_contents_t type = arc_buf_type(hdr); - arc_adapt(size, state); + if (do_adapt) + arc_adapt(size, state); /* * If arc_size is currently overflowing, and has grown past our @@ -5935,8 +5936,9 @@ top: * do this after we've called arc_access() to * avoid hitting an assert in remove_reference(). */ + arc_adapt(arc_hdr_size(hdr), hdr->b_l1hdr.b_state); arc_access(hdr, hash_lock); - arc_hdr_alloc_pabd(hdr); + arc_hdr_alloc_pabd(hdr, B_FALSE); } ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL); size = arc_hdr_size(hdr); @@ -6350,7 +6352,7 @@ arc_release(arc_buf_t *buf, void *tag) if (arc_can_share(hdr, lastbuf)) { arc_share_buf(hdr, lastbuf); } else { - arc_hdr_alloc_pabd(hdr); + arc_hdr_alloc_pabd(hdr, B_TRUE); abd_copy_from_buf(hdr->b_l1hdr.b_pabd, buf->b_data, psize); } @@ -6513,7 +6515,7 @@ arc_write_ready(zio_t *zio) * the data into it; otherwise, we share the data directly if we can. */ if (zfs_abd_scatter_enabled || !arc_can_share(hdr, buf)) { - arc_hdr_alloc_pabd(hdr); + arc_hdr_alloc_pabd(hdr, B_TRUE); /* * Ideally, we would always copy the io_abd into b_pabd, but the
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