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 9D081C19F4F for ; Mon, 29 Apr 2024 13:48:30 +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=7atq02NMLxl5ym4FntoXCysokW3IWSRkkjwzlxiaA28=; b=naNDQsu9FRH3A64Yqp44zEPpYF rasS20Zi4pp+nf8rZWf07tT/IqCmDhG5F+uTLDyCyfCkOKKxkbzjaroBAvZxT9RaWoEgKXGezSKdZ 8XInz+vColo/NJCNNBJcuLJqsgGIHX8R4CUJguJafz6ChjdZbWPooF9hnL8/l5ARrgQjx64ITt4EQ yqvW4DCC7d5L2y7LWMopjdM5rW1nkxswpQku1vnInEaWsi6wwoyHQw7XrbCG04B7Siiaj8TUuECgC 2Flwzb1WS7gXNlALdnZApx9eQiqwCw+LhZKJnERuVdPCVZ4TCdHbPOqNLC+pweew8hgnGpGlMiX5f tFewUXNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s1RMr-00000002zur-1R0O; Mon, 29 Apr 2024 13:48:29 +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 1s1RMn-00000002zmZ-12sW for linux-um@lists.infradead.org; Mon, 29 Apr 2024 13:48:26 +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=7atq02NMLxl5ym4FntoXCysokW3IWSRkkjwzlxiaA28=; t=1714398498; x=1715608098; b=ObMF1tfE31awzRTX7+JkYQSlXVzx1wRfn/nzQIrhUZIAO0TnZwwtyuaZI6zScU+qpe5M8efTttI MwFVMDpoLMHSu58nI8ns0atqEaNKjr+CaR4EC/i9q8bKVda4ReABvF1pRYmpz/RLRcW7uQ3J1ZOnR 6DZFdr3gOi7fEfeU0gMXc2JrlrT6GcgqT+XiNS5CZjSxgr9hptrL2Q0mzBPsGRJRxVa22/IBxGhgh e4O4MHRRcvxWLz6wBAmlC5NNbvegxZkIVUit5pBhDfxhy5xisXF2GP/kLUNLm9H4+RakwYCgZQqtd A4HK/czQpra02syonvSxdXuDDWJpx812uEGg==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1s1RMc-0000000CW0d-3oOM; Mon, 29 Apr 2024 15:48:15 +0200 From: benjamin@sipsolutions.net To: linux-um@lists.infradead.org Cc: Benjamin Berg Subject: [PATCH v2 00/12] Rework stub syscall and page table handling Date: Mon, 29 Apr 2024 15:47:47 +0200 Message-ID: <20240429134759.244517-1-benjamin@sipsolutions.net> X-Mailer: git-send-email 2.44.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240429_064825_560741_0A4A7FA7 X-CRM114-Status: GOOD ( 12.39 ) 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 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 | 35 +- 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 | 1 + arch/x86/um/shared/sysdep/stub_32.h | 29 +- arch/x86/um/shared/sysdep/stub_64.h | 23 +- arch/x86/um/stub_32.S | 56 --- arch/x86/um/stub_64.S | 50 --- arch/x86/um/tls_32.c | 1 + 33 files changed, 543 insertions(+), 1368 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 -- 2.44.0