From nobody Mon Feb 9 00:31:26 2026 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 84EDB54F8C for ; Mon, 8 Jul 2024 09:29:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720430962; cv=none; b=TsvICwTcCi47glcV5yuyfpQcFEYFvksbC/UVjMA+OhtZMeBvCiRWaNHCQ2KmNo+r88JmmXTu5lf0WuBCyRNpJ28TRCbNktTPi49eXu6BPhHWH/13nWxSYR5FacQaz9NQjAHkgAZXTdLWOND0G15ZGXKDpmEPnxqN+QU21BaCKtk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720430962; c=relaxed/simple; bh=Jzk70wrwgyLqpwlKGY57fPB8+FPqSQUySn0ZoqTIHvk=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=SLJZqizgTIUwfj68J0gcC9ABQNU4WE+r5c8pCO2hhCDJcJ1eV2NF9O7JZBtzuWgo+UIa6X6zZzAVuX4TXNPybYx8MCp/DHqumfeN52D7IAmgG7ohOI1wnB++17VDQav6J3z4oQ603MVKT4Mh3kw1leqc+ZiFUtkY2FbQom/UxvA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Og/wOdK6; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Og/wOdK6" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=rOfuhX/Ngd/1oTixnYxtLLU1jaqckcc7jQQl+4rPfhA=; b=Og/wOdK6h9PcPwOSR4GCF6P3Qr mHdhMeReDtpf2IlRf+7AnhsUrNg2PkOZysnu6MdE/GHx4UnP0J7ieaIqJRORB8PMWKMBIjcfJ703Y W3XIyPy5i5mUmfUv+oUsLH8YhX7ShORQ0/477eJgzAsQf4PTEN1NGrbiXKCOXLlNlPoMfYoevRDGM VMXiIG5/m4qz0lnjeguJOEeBbzwdUrswAWlQhVYZe/DtQoPnlU4+u/1tFUtTbfD2HD/4b6P+jz2NJ VTWA0JHmfE8DLJ1yYzcLoYcRYFBFsKYzPpZ3UCCk/sRNoGmT9ao7+DdntbXzUEYqoUvZCzEy46X/o XNlNjXEA==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1sQkgN-00000006hOc-354R; Mon, 08 Jul 2024 09:29:15 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id 1D5A3302440; Mon, 8 Jul 2024 11:29:13 +0200 (CEST) Message-Id: <20240708092415.801757710@infradead.org> User-Agent: quilt/0.65 Date: Mon, 08 Jul 2024 11:12:47 +0200 From: Peter Zijlstra To: mingo@kernel.org, andrii@kernel.org Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, rostedt@goodmis.org, mhiramat@kernel.org, oleg@redhat.com, jolsa@kernel.org, clm@meta.com, paulmck@kernel.org Subject: [PATCH 06/10] perf/uprobe: Split uprobe_unregister() References: <20240708091241.544262971@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" With uprobe_unregister() having grown a synchronize_srcu(), it becomes fairly slow to call. Esp. since both users of this API call it in a loop. Peel off the sync_srcu() and do it once, after the loop. Signed-off-by: Peter Zijlstra (Intel) Acked-by: Masami Hiramatsu (Google) --- include/linux/uprobes.h | 8 ++++++-- kernel/events/uprobes.c | 8 ++++++-- kernel/trace/bpf_trace.c | 6 ++++-- kernel/trace/trace_uprobe.c | 6 +++++- 4 files changed, 21 insertions(+), 7 deletions(-) --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -113,7 +113,8 @@ extern int uprobe_write_opcode(struct ar extern int uprobe_register(struct inode *inode, loff_t offset, struct upro= be_consumer *uc); extern int uprobe_register_refctr(struct inode *inode, loff_t offset, loff= _t ref_ctr_offset, struct uprobe_consumer *uc); extern int uprobe_apply(struct inode *inode, loff_t offset, struct uprobe_= consumer *uc, bool); -extern void uprobe_unregister(struct inode *inode, loff_t offset, struct u= probe_consumer *uc); +extern void uprobe_unregister_nosync(struct inode *inode, loff_t offset, s= truct uprobe_consumer *uc); +extern void uprobe_unregister_sync(void); extern int uprobe_mmap(struct vm_area_struct *vma); extern void uprobe_munmap(struct vm_area_struct *vma, unsigned long start,= unsigned long end); extern void uprobe_start_dup_mmap(void); @@ -163,7 +164,10 @@ uprobe_apply(struct inode *inode, loff_t return -ENOSYS; } static inline void -uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_consum= er *uc) +uprobe_unregister_nosync(struct inode *inode, loff_t offset, struct uprobe= _consumer *uc) +{ +} +static inline void uprobes_unregister_sync(void) { } static inline int uprobe_mmap(struct vm_area_struct *vma) --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1126,7 +1126,7 @@ __uprobe_unregister(struct uprobe *uprob * @offset: offset from the start of the file. * @uc: identify which probe if multiple probes are colocated. */ -void uprobe_unregister(struct inode *inode, loff_t offset, struct uprobe_c= onsumer *uc) +void uprobe_unregister_nosync(struct inode *inode, loff_t offset, struct u= probe_consumer *uc) { struct uprobe *uprobe; =20 @@ -1138,10 +1138,14 @@ void uprobe_unregister(struct inode *ino __uprobe_unregister(uprobe, uc); mutex_unlock(&uprobe->register_mutex); put_uprobe(uprobe); +} +EXPORT_SYMBOL_GPL(uprobe_unregister_nosync); =20 +void uprobe_unregister_sync(void) +{ synchronize_srcu(&uprobes_srcu); } -EXPORT_SYMBOL_GPL(uprobe_unregister); +EXPORT_SYMBOL_GPL(uprobe_unregister_sync); =20 /* * __uprobe_register - register a probe --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -3181,9 +3181,11 @@ static void bpf_uprobe_unregister(struct u32 i; =20 for (i =3D 0; i < cnt; i++) { - uprobe_unregister(d_real_inode(path->dentry), uprobes[i].offset, - &uprobes[i].consumer); + uprobe_unregister_nosync(d_real_inode(path->dentry), uprobes[i].offset, + &uprobes[i].consumer); } + if (cnt) + uprobe_unregister_sync(); } =20 static void bpf_uprobe_multi_link_release(struct bpf_link *link) --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1104,6 +1104,7 @@ static int trace_uprobe_enable(struct tr static void __probe_event_disable(struct trace_probe *tp) { struct trace_uprobe *tu; + bool sync =3D false; =20 tu =3D container_of(tp, struct trace_uprobe, tp); WARN_ON(!uprobe_filter_is_empty(tu->tp.event->filter)); @@ -1112,9 +1113,12 @@ static void __probe_event_disable(struct if (!tu->inode) continue; =20 - uprobe_unregister(tu->inode, tu->offset, &tu->consumer); + uprobe_unregister_nosync(tu->inode, tu->offset, &tu->consumer); + sync =3D true; tu->inode =3D NULL; } + if (sync) + uprobe_unregister_sync(); } =20 static int probe_event_enable(struct trace_event_call *call,