From nobody Fri Nov 21 15:03:01 2025 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4dCdkY1wTZz6HKZ8 for ; Fri, 21 Nov 2025 15:03:01 +0000 (UTC) (envelope-from git@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) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R12" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dCdkY0xr1z3lVK for ; Fri, 21 Nov 2025 15:03:01 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763737381; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=YvydlxhihUNsj49gEanuZlWQQLunMiBDGAIif1akmEI=; b=tK3hRVon8Wcd/1EsMMFVQB7w3169MKrgbwvwHsvxg7UMuDtwFL4jmsVFZ3vuMMEyVgv0bs 0+retQ6MOL5vO5qkFFblGsm5tAu1zyM8afm/zy6zHwVnYmCzpfxNodjxa8oGXcb7w9kgey RlhqKvmKvhIsgCb1dO9Zlwr6skqjpUCsui67oVyo+cu2TzHMJtsFu14o0jboB8+BXErLsp Z7ddw6/3K0Gp29IRJQ8tc63/OuKJatfwnvOkdlmuMVUT9x8tK3uXjMRTx/GoGyMJl2Lj3m R89L2jigCXWeR91B+2alS81aZ0EPRASMF7DyITJoU599AtpQMqtO8gIVGtTkyA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763737381; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=YvydlxhihUNsj49gEanuZlWQQLunMiBDGAIif1akmEI=; b=iLy/mkVdujnVSGhDmgzhiiBhHV2HUg2Q03vq0b4gtzzuBhjhDrdM3UDRgmSa7zfa/Qmlwq zourOC6Y4udPf3hSaUZjTaL1McT2EjMWrhN0eIzO5YDL9TLx1TkzCyG80Saa9/bKofiR8a 9jE2FNX35UuXfYLXY5wpBVmm/Gm2BCePV5YOUymVH75jYtMqtxKP/N76kqp+n2/ipvjDaV TLb2V9VAlD9UrnYKz9Ldiza0msE+gCFVOxDO4xFD1mtjULP0y7BSsg30CNCcqoD5QHJy44 Qa1mVqpTt0ZH6EesEgfKXQU7sG69S/gvxmphKyTKU05ZBmAEYz1HQo5hTZgkJg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1763737381; a=rsa-sha256; cv=none; b=k7IBjvuCfqYzO7HUbjJsyFfSszir2BkGHgwz50dlapK/4pNSpNoxFeFrvW6l56EuHq7Hvq z3nMO52+Vh1bOOp4VWBK7fxQC2Ed3EhGhEjPfPSkkNXBSrP+oRXnBsH8q3U7USOEEK0cN+ E5QiVwYm6x45YjkgAcQoO0IZGZL3kRKuglnZuepNayCh6aqIflNTh71nlae/kLtNKTXili ZXw4+RmgczHPgsoV5ktfcut5f86FeOpuxfQqw3O/8hdHxTo1SV+htsr0wb06B1y9FxDfa4 acJlECTTl3UQ8ae8It1Ju90+ti47BRMCCeGRt3jf8kJgJbwozOCMRRxW4xKbrQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4dCdkY0TS0z2f7 for ; Fri, 21 Nov 2025 15:03:01 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 31208 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Fri, 21 Nov 2025 15:03:01 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Konstantin Belousov Subject: git: b9fc7628dbb2 - main - vm_page_free_prep(): convert PG_ZERO zeroed page check to use sf_buf List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: kib X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: b9fc7628dbb24b55cbb8791c83bd69f73cfadf23 Auto-Submitted: auto-generated Date: Fri, 21 Nov 2025 15:03:01 +0000 Message-Id: <69207f25.31208.26d1a968@gitrepo.freebsd.org> The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=b9fc7628dbb24b55cbb8791c83bd69f73cfadf23 commit b9fc7628dbb24b55cbb8791c83bd69f73cfadf23 Author: Konstantin Belousov AuthorDate: 2025-11-21 08:57:17 +0000 Commit: Konstantin Belousov CommitDate: 2025-11-21 15:02:21 +0000 vm_page_free_prep(): convert PG_ZERO zeroed page check to use sf_buf Make the check MI by allocating sf_buf in non-blockable manner. For DMAP arches, this should be nop since sf_buf allocation cannot fail trivially. For non-DMAP arches, we get the checks activated unless there is serious sf_buf pressure, which typically should be not. The context for vm_page_free_prep() should be ready to block on some VM mutexes, which should make it reasonable to block on sf_buf list lock. Move the code to INVARIANTS build from DIAGNOSTIC, and control its activation with the sysctl debug.vm_check_pg_zero. Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D53850 --- sys/vm/vm_extern.h | 3 +++ sys/vm/vm_page.c | 32 +++++++++++++++++++++++++------- 2 files changed, 28 insertions(+), 7 deletions(-) diff --git a/sys/vm/vm_extern.h b/sys/vm/vm_extern.h index 1fd6518cf4ed..d0e005088745 100644 --- a/sys/vm/vm_extern.h +++ b/sys/vm/vm_extern.h @@ -164,5 +164,8 @@ vm_addr_ok(vm_paddr_t pa, vm_paddr_t size, u_long alignment, return (vm_addr_align_ok(pa, alignment) && vm_addr_bound_ok(pa, size, boundary)); } + +extern bool vm_check_pg_zero; + #endif /* _KERNEL */ #endif /* !_VM_EXTERN_H_ */ diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c index 16878604fa11..b39d665f9e0f 100644 --- a/sys/vm/vm_page.c +++ b/sys/vm/vm_page.c @@ -84,6 +84,7 @@ #include #include #include +#include #include #include #include @@ -145,6 +146,13 @@ SYSCTL_ULONG(_vm_stats_page, OID_AUTO, nofreeq_size, CTLFLAG_RD, &nofreeq_size, 0, "Size of the nofree queue"); +#ifdef INVARIANTS +bool vm_check_pg_zero = false; +SYSCTL_BOOL(_debug, OID_AUTO, vm_check_pg_zero, CTLFLAG_RWTUN, + &vm_check_pg_zero, 0, + "verify content of freed zero-filled pages"); +#endif + /* * bogus page -- for I/O to/from partially complete buffers, * or for paging into sparsely invalid regions. @@ -4050,14 +4058,24 @@ vm_page_free_prep(vm_page_t m) */ atomic_thread_fence_acq(); -#if defined(DIAGNOSTIC) && defined(PHYS_TO_DMAP) - if (PMAP_HAS_DMAP && (m->flags & PG_ZERO) != 0) { - uint64_t *p; +#ifdef INVARIANTS + if (vm_check_pg_zero && (m->flags & PG_ZERO) != 0) { + struct sf_buf *sf; + unsigned long *p; int i; - p = (uint64_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)); - for (i = 0; i < PAGE_SIZE / sizeof(uint64_t); i++, p++) - KASSERT(*p == 0, ("vm_page_free_prep %p PG_ZERO %d %jx", - m, i, (uintmax_t)*p)); + + sched_pin(); + sf = sf_buf_alloc(m, SFB_CPUPRIVATE | SFB_NOWAIT); + if (sf != NULL) { + p = (unsigned long *)sf_buf_kva(sf); + for (i = 0; i < PAGE_SIZE / sizeof(*p); i++, p++) { + KASSERT(*p == 0, + ("zerocheck failed page %p PG_ZERO %d %jx", + m, i, (uintmax_t)*p)); + } + sf_buf_free(sf); + } + sched_unpin(); } #endif if ((m->oflags & VPO_UNMANAGED) == 0) {