From owner-svn-src-head@freebsd.org Sat May 11 02:13:53 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 19118158F0DA; Sat, 11 May 2019 02:13:53 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id B083D6E038; Sat, 11 May 2019 02:13:52 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 8C117D1BF; Sat, 11 May 2019 02:13:52 +0000 (UTC) (envelope-from dougm@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x4B2Dq4b088623; Sat, 11 May 2019 02:13:52 GMT (envelope-from dougm@FreeBSD.org) Received: (from dougm@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x4B2Dq9U088622; Sat, 11 May 2019 02:13:52 GMT (envelope-from dougm@FreeBSD.org) Message-Id: <201905110213.x4B2Dq9U088622@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: dougm set sender to dougm@FreeBSD.org using -f From: Doug Moore Date: Sat, 11 May 2019 02:13:52 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r347477 - head/sys/kern X-SVN-Group: head X-SVN-Commit-Author: dougm X-SVN-Commit-Paths: head/sys/kern X-SVN-Commit-Revision: 347477 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: B083D6E038 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.91 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.996,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.92)[-0.919,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 May 2019 02:13:53 -0000 Author: dougm Date: Sat May 11 02:13:52 2019 New Revision: 347477 URL: https://svnweb.freebsd.org/changeset/base/347477 Log: Revert r347469. Approved by: kib (mentor) Modified: head/sys/kern/subr_blist.c Modified: head/sys/kern/subr_blist.c ============================================================================== --- head/sys/kern/subr_blist.c Fri May 10 23:52:17 2019 (r347476) +++ head/sys/kern/subr_blist.c Sat May 11 02:13:52 2019 (r347477) @@ -192,41 +192,31 @@ bitrange(int n, int count) /* - * Find the first bit set in a u_daddr_t. + * Use binary search, or a faster method, to find the 1 bit in a u_daddr_t. + * Assumes that the argument has only one bit set. */ static inline int -generic_bitpos(u_daddr_t mask) +bitpos(u_daddr_t mask) { int hi, lo, mid; - lo = 0; - hi = BLIST_BMAP_RADIX; - while (lo + 1 < hi) { - mid = (lo + hi) >> 1; - if (mask & bitrange(0, mid)) - hi = mid; - else - lo = mid; - } - return (lo); -} - -static inline int -bitpos(u_daddr_t mask) -{ - - switch (sizeof(mask)) { + switch (sizeof(mask)) { #ifdef HAVE_INLINE_FFSLL - case sizeof(long long): - return (ffsll(mask) - 1); + case sizeof(long long): + return (ffsll(mask) - 1); #endif -#ifdef HAVE_INLINE_FFS - case sizeof(int): - return (ffs(mask) - 1); -#endif - default: - return (generic_bitpos(mask)); - } + default: + lo = 0; + hi = BLIST_BMAP_RADIX; + while (lo + 1 < hi) { + mid = (lo + hi) >> 1; + if ((mask >> mid) != 0) + lo = mid; + else + hi = mid; + } + return (lo); + } } /* @@ -542,8 +532,7 @@ blist_stats(blist_t bl, struct sbuf *s) struct gap_stats gstats; struct gap_stats *stats = &gstats; daddr_t i, nodes, radix; - u_daddr_t diff, mask; - int digit; + u_daddr_t bit, diff, mask; init_gap_stats(stats); nodes = 0; @@ -581,9 +570,9 @@ blist_stats(blist_t bl, struct sbuf *s) if (gap_stats_counting(stats)) diff ^= 1; while (diff != 0) { - digit = bitpos(diff); - update_gap_stats(stats, i + digit); - diff ^= bitrange(digit, 1); + bit = diff & -diff; + update_gap_stats(stats, i + bitpos(bit)); + diff ^= bit; } } nodes += radix_to_skip(radix); @@ -787,7 +776,7 @@ static daddr_t blst_meta_alloc(blmeta_t *scan, daddr_t cursor, daddr_t count, u_daddr_t radix) { daddr_t blk, i, r, skip; - u_daddr_t mask; + u_daddr_t bit, mask; bool scan_from_start; int digit; @@ -819,7 +808,8 @@ blst_meta_alloc(blmeta_t *scan, daddr_t cursor, daddr_ * Examine the nonempty subtree associated with each bit set in mask. */ do { - digit = bitpos(mask); + bit = mask & -mask; + digit = bitpos(bit); i = 1 + digit * skip; if (count <= scan[i].bm_bighint) { /* @@ -829,12 +819,12 @@ blst_meta_alloc(blmeta_t *scan, daddr_t cursor, daddr_ count, radix); if (r != SWAPBLK_NONE) { if (scan[i].bm_bitmap == 0) - scan->bm_bitmap ^= bitrange(digit, 1); + scan->bm_bitmap ^= bit; return (r); } } cursor = blk; - } while ((mask ^= bitrange(digit, 1)) != 0); + } while ((mask ^= bit) != 0); /* * We couldn't allocate count in this subtree. If the whole tree was @@ -1029,7 +1019,7 @@ static void blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t radix, int tab) { daddr_t skip; - u_daddr_t mask; + u_daddr_t bit, mask; int digit; if (radix == BLIST_BMAP_RADIX) { @@ -1061,10 +1051,11 @@ blst_radix_print(blmeta_t *scan, daddr_t blk, daddr_t mask = scan->bm_bitmap; /* Examine the nonempty subtree associated with each bit set in mask */ do { - digit = bitpos(mask); + bit = mask & -mask; + digit = bitpos(bit); blst_radix_print(&scan[1 + digit * skip], blk + digit * radix, radix, tab); - } while ((mask ^= bitrange(digit, 1)) != 0); + } while ((mask ^= bit) != 0); tab -= 4; printf(