From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1AADEC25B7D for ; Fri, 24 May 2024 21:41:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=sKPdTSDjp7qCQ6w61DqAF2obv3DacK+hnAnaROquCVM=; b=fNaFt0OMXc59pQh33HpaSVUBHq joIZgtVPUf8fuerQs3C0S+FMpaZAWPTN8ZZRklvzS4VW53d8cH9/D56PJ3sXW2sb3PwHiW1LiGgxR 3SHrxoTYSgAxTSIQbyVirN/9m5WyY0hLeQq13l5jYk7Ax8xFyWqLSBgyKcnzAfGabblThpsWKKhYZ sNbXOfqFf6WFgUCw+SPcTd4E8wYdnK6GJaFDa5W8j+JiZb9GD4gxAkn8Io76zeX/0VbvMNUZr0vob vYx2jMoXLbgowxKED1SxUI0+Qt8GhseyyL06PTlkOIlv7z61Qcbpy2CkasFOXANdENjo+n1FmzMIU P1B0Zjig==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sAcf2-00000009wao-1JTf; Fri, 24 May 2024 21:41:12 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sAcev-00000009wYw-01xV for linux-um@lists.infradead.org; Fri, 24 May 2024 21:41:10 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=Content-Transfer-Encoding:MIME-Version: Message-ID:Date:Subject:Cc:To:From:Content-Type:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-To:Resent-Cc: Resent-Message-ID:In-Reply-To:References; bh=sKPdTSDjp7qCQ6w61DqAF2obv3DacK+hnAnaROquCVM=; t=1716586862; x=1717796462; b=jKAkikozRXqWD+pZzhQLrzqRPoCwZCTcY/6VcL8XhDEL/I3Wia0mZzgpQJmEDQxB4WKRSHTzemx gr2PsvYQKM99SzDm6SnJ/u4H6tzs1M3kPzx1p7v9ERrYBZXWJm6x7Lw+E5MPC4mcBRUWd80LYyQH6 9UjsY6F+G5FmrtnIp8Gq6TvPhWMggR/8xi9ThmPFsCOkxQhqvhvSg06CdGP4hG0V2Lg99kOybKEIq KLmS4slcqhP3LKGTea4Beywl6v+7wiHsZn3W0WN8RqyPD2xdtOYmLwkqPk7hIHr3lG9zt9lKWAVGS Jrcp0rNXp2+Iya8bwaf8BHZzIu9xR0B7f9Lg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1sAcep-00000008ke7-00s7; Fri, 24 May 2024 23:40:59 +0200 From: benjamin@sipsolutions.net To: linux-um@lists.infradead.org Cc: Benjamin Berg Subject: [PATCH v3 00/12] Rework stub syscall and page table handling Date: Fri, 24 May 2024 23:37:06 +0200 Message-ID: <20240524213718.1757703-1-benjamin@sipsolutions.net> X-Mailer: git-send-email 2.45.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240524_144105_289899_3744FCCA X-CRM114-Status: GOOD ( 12.32 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org From: Benjamin Berg This patchset reworks the stub syscall handling and also redos how page table updates are tracked and synchronized. Some of this originated in the SECCOMP patchset, but it became clear that these refactorings make sense independently as they result in a considerably fewer page faults. As an example, these changes bring the runtime of one of the hostapd hwsim test modules from 121 seconds down to 103 seconds. Actual results will depend heavily on how pagefault heavy the workload is. Lowering the amount of pagefaults is due to proactively syncing PTEs that are set (and were previously unset) and also delaying synchronization so that multiple updates can be done in one step rather than requiring multiple task switches. This refactoring also fixes various odd corner cases in how UML was handling memory and cloning of MMs. As part of this work, support for LDTs has been dropped. My expectation is that this is not a problem as it should only be needed by legacy applications. Changes in v2: * Address comments from Tiwei Bie * Remove duplicate report_enomem declaration Changes in v3: * Remove more left over code from copy_context_skas0 removal * Fix mprotect syscall in stub Benjamin Berg (12): um: Remove stub-data.h include from common-offsets.h um: Create signal stack memory assignment in stub_data um: Add generic stub_syscall6 function um: Rework syscall handling um: compress memory related stub syscalls while adding them um: remove LDT support um: remove copy_context_skas0 um: Delay flushing syscalls until the thread is restarted um: Do not flush MM in flush_thread um: remove force_flush_all from fork_handler um: simplify and consolidate TLB updates um: refactor TLB update handling arch/um/drivers/ubd_kern.c | 2 - arch/um/include/asm/mmu.h | 10 +- arch/um/include/asm/mmu_context.h | 2 - arch/um/include/asm/pgtable.h | 32 ++ arch/um/include/asm/tlbflush.h | 46 +- arch/um/include/shared/as-layout.h | 2 +- arch/um/include/shared/common-offsets.h | 5 - arch/um/include/shared/os.h | 27 +- arch/um/include/shared/skas/mm_id.h | 2 +- arch/um/include/shared/skas/skas.h | 2 + arch/um/include/shared/skas/stub-data.h | 36 +- arch/um/include/shared/user.h | 8 + arch/um/kernel/exec.c | 9 - arch/um/kernel/process.c | 2 - arch/um/kernel/skas/Makefile | 9 +- arch/um/kernel/skas/clone.c | 48 --- arch/um/kernel/skas/mmu.c | 33 +- arch/um/kernel/skas/process.c | 18 + arch/um/kernel/skas/stub.c | 69 +++ arch/um/kernel/tlb.c | 551 ++++-------------------- arch/um/kernel/trap.c | 15 +- arch/um/os-Linux/skas/mem.c | 248 ++++++----- arch/um/os-Linux/skas/process.c | 121 +----- arch/um/os-Linux/start_up.c | 1 + arch/x86/um/Makefile | 4 +- arch/x86/um/asm/mm_context.h | 70 --- arch/x86/um/ldt.c | 380 ---------------- arch/x86/um/shared/sysdep/stub.h | 2 +- arch/x86/um/shared/sysdep/stub_32.h | 45 +- arch/x86/um/shared/sysdep/stub_64.h | 41 +- arch/x86/um/stub_32.S | 56 --- arch/x86/um/stub_64.S | 50 --- arch/x86/um/tls_32.c | 1 + 33 files changed, 535 insertions(+), 1412 deletions(-) delete mode 100644 arch/um/kernel/skas/clone.c create mode 100644 arch/um/kernel/skas/stub.c delete mode 100644 arch/x86/um/asm/mm_context.h delete mode 100644 arch/x86/um/ldt.c delete mode 100644 arch/x86/um/stub_32.S delete mode 100644 arch/x86/um/stub_64.S -- 2.45.1