From owner-svn-src-all@freebsd.org Sun Jul 7 18:44:53 2019 Return-Path: Delivered-To: svn-src-all@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 62B2D15EB390; Sun, 7 Jul 2019 18:44:53 +0000 (UTC) (envelope-from mav@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 064506D4A8; Sun, 7 Jul 2019 18:44:53 +0000 (UTC) (envelope-from mav@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 CC553527E; Sun, 7 Jul 2019 18:44:52 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x67IiqSw075122; Sun, 7 Jul 2019 18:44:52 GMT (envelope-from mav@FreeBSD.org) Received: (from mav@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x67IipTD075118; Sun, 7 Jul 2019 18:44:51 GMT (envelope-from mav@FreeBSD.org) Message-Id: <201907071844.x67IipTD075118@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mav set sender to mav@FreeBSD.org using -f From: Alexander Motin Date: Sun, 7 Jul 2019 18:44:51 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r349823 - in stable/12/sys: geom kern sys X-SVN-Group: stable-12 X-SVN-Commit-Author: mav X-SVN-Commit-Paths: in stable/12/sys: geom kern sys X-SVN-Commit-Revision: 349823 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 064506D4A8 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.95)[-0.946,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; ASN(0.00)[asn:12874, ipnet:2000::/3, country:IT] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 07 Jul 2019 18:44:53 -0000 Author: mav Date: Sun Jul 7 18:44:51 2019 New Revision: 349823 URL: https://svnweb.freebsd.org/changeset/base/349823 Log: MFC r349178: Optimize kern.geom.conf* sysctls. On large systems those sysctls may generate megabytes of output. Before this change sbuf(9) code was resizing buffer by 4KB each time many times, generating tons of TLB shootdowns. Unfortunately in this case existing sbuf_new_for_sysctl() mechanism, supposed to help with this issue, is not applicable, since all the sbuf writes are done in different kernel thread. This change improves situation in two ways: - on first sysctl call, not providing any output buffer, it sets special sbuf drain function, just counting the data and so not needing big buffer; - on second sysctl call it uses as initial buffer size value saved on previous call, so that in most cases there will be no reallocation, unless GEOM topology changed significantly. Modified: stable/12/sys/geom/geom_kern.c stable/12/sys/kern/imgact_elf.c stable/12/sys/kern/subr_sbuf.c stable/12/sys/sys/sbuf.h Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/geom/geom_kern.c ============================================================================== --- stable/12/sys/geom/geom_kern.c Sun Jul 7 18:42:25 2019 (r349822) +++ stable/12/sys/geom/geom_kern.c Sun Jul 7 18:44:51 2019 (r349823) @@ -157,42 +157,51 @@ g_init(void) } static int -sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS) +sysctl_kern_geom_confany(struct sysctl_req *req, g_event_t *func, size_t *hint) { - int error; + size_t len = 0; + int error = 0; struct sbuf *sb; - sb = sbuf_new_auto(); - g_waitfor_event(g_conftxt, sb, M_WAITOK, NULL); - error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); + if (req->oldptr == NULL) { + sb = sbuf_new(NULL, NULL, PAGE_SIZE, SBUF_FIXEDLEN | + SBUF_INCLUDENUL); + sbuf_set_drain(sb, sbuf_count_drain, &len); + g_waitfor_event(func, sb, M_WAITOK, NULL); + req->oldidx = *hint = len; + } else { + sb = sbuf_new(NULL, NULL, *hint, SBUF_AUTOEXTEND | + SBUF_INCLUDENUL); + g_waitfor_event(func, sb, M_WAITOK, NULL); + *hint = sbuf_len(sb); + error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb)); + } sbuf_delete(sb); return error; } + +static int +sysctl_kern_geom_conftxt(SYSCTL_HANDLER_ARGS) +{ + static size_t hint = PAGE_SIZE; + + return (sysctl_kern_geom_confany(req, g_conftxt, &hint)); +} static int sysctl_kern_geom_confdot(SYSCTL_HANDLER_ARGS) { - int error; - struct sbuf *sb; + static size_t hint = PAGE_SIZE; - sb = sbuf_new_auto(); - g_waitfor_event(g_confdot, sb, M_WAITOK, NULL); - error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); - sbuf_delete(sb); - return error; + return (sysctl_kern_geom_confany(req, g_confdot, &hint)); } - + static int sysctl_kern_geom_confxml(SYSCTL_HANDLER_ARGS) { - int error; - struct sbuf *sb; + static size_t hint = PAGE_SIZE; - sb = sbuf_new_auto(); - g_waitfor_event(g_confxml, sb, M_WAITOK, NULL); - error = SYSCTL_OUT(req, sbuf_data(sb), sbuf_len(sb) + 1); - sbuf_delete(sb); - return error; + return (sysctl_kern_geom_confany(req, g_confxml, &hint)); } SYSCTL_NODE(_kern, OID_AUTO, geom, CTLFLAG_RW, 0, "GEOMetry management"); Modified: stable/12/sys/kern/imgact_elf.c ============================================================================== --- stable/12/sys/kern/imgact_elf.c Sun Jul 7 18:42:25 2019 (r349822) +++ stable/12/sys/kern/imgact_elf.c Sun Jul 7 18:44:51 2019 (r349823) @@ -1423,7 +1423,6 @@ static void __elfN(puthdr)(struct thread *, void *, si static void __elfN(putnote)(struct note_info *, struct sbuf *); static size_t register_note(struct note_info_list *, int, outfunc_t, void *); static int sbuf_drain_core_output(void *, const char *, int); -static int sbuf_drain_count(void *arg, const char *data, int len); static void __elfN(note_fpregset)(void *, struct sbuf *, size_t *); static void __elfN(note_prpsinfo)(void *, struct sbuf *, size_t *); @@ -1553,19 +1552,6 @@ sbuf_drain_core_output(void *arg, const char *data, in return (len); } -/* - * Drain into a counter. - */ -static int -sbuf_drain_count(void *arg, const char *data __unused, int len) -{ - size_t *sizep; - - sizep = (size_t *)arg; - *sizep += len; - return (len); -} - int __elfN(coredump)(struct thread *td, struct vnode *vp, off_t limit, int flags) { @@ -2342,7 +2328,7 @@ note_procstat_files(void *arg, struct sbuf *sb, size_t if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); - sbuf_set_drain(sb, sbuf_drain_count, &size); + sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_filedesc_out(p, sb, -1, filedesc_flags); @@ -2393,7 +2379,7 @@ note_procstat_vmmap(void *arg, struct sbuf *sb, size_t if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); - sbuf_set_drain(sb, sbuf_drain_count, &size); + sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PROC_LOCK(p); kern_proc_vmmap_out(p, sb, -1, vmmap_flags); @@ -2521,7 +2507,7 @@ __elfN(note_procstat_auxv)(void *arg, struct sbuf *sb, if (sb == NULL) { size = 0; sb = sbuf_new(NULL, NULL, 128, SBUF_FIXEDLEN); - sbuf_set_drain(sb, sbuf_drain_count, &size); + sbuf_set_drain(sb, sbuf_count_drain, &size); sbuf_bcat(sb, &structsize, sizeof(structsize)); PHOLD(p); proc_getauxv(curthread, p, sb); Modified: stable/12/sys/kern/subr_sbuf.c ============================================================================== --- stable/12/sys/kern/subr_sbuf.c Sun Jul 7 18:42:25 2019 (r349822) +++ stable/12/sys/kern/subr_sbuf.c Sun Jul 7 18:44:51 2019 (r349823) @@ -342,6 +342,21 @@ sbuf_setpos(struct sbuf *s, ssize_t pos) } /* + * Drain into a counter. Counts amount of data without prodicing output. + * Useful for cases like sysctl, where user may first request only size. + * This allows to avoid pointless allocation/freeing of large buffers. + */ +int +sbuf_count_drain(void *arg, const char *data __unused, int len) +{ + size_t *sizep; + + sizep = (size_t *)arg; + *sizep += len; + return (len); +} + +/* * Set up a drain function and argument on an sbuf to flush data to * when the sbuf buffer overflows. */ Modified: stable/12/sys/sys/sbuf.h ============================================================================== --- stable/12/sys/sys/sbuf.h Sun Jul 7 18:42:25 2019 (r349822) +++ stable/12/sys/sys/sbuf.h Sun Jul 7 18:44:51 2019 (r349823) @@ -103,6 +103,7 @@ void sbuf_start_section(struct sbuf *, ssize_t *); ssize_t sbuf_end_section(struct sbuf *, ssize_t, size_t, int); void sbuf_hexdump(struct sbuf *, const void *, int, const char *, int); +int sbuf_count_drain(void *arg, const char *data, int len); void sbuf_putbuf(struct sbuf *); #ifdef _KERNEL