From nobody Fri Sep 12 14:31:10 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD2C4C77B7D for ; Mon, 15 May 2023 18:07:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245088AbjEOSHb (ORCPT ); Mon, 15 May 2023 14:07:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243192AbjEOSGp (ORCPT ); Mon, 15 May 2023 14:06:45 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 925A61F307 for ; Mon, 15 May 2023 11:03:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684173826; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: references:references; bh=F5ZFnFWd0bfXvbTVZzhDKmwHy0T6x+spMFYT61y9M6E=; b=g3vAmX6c3AFB9Rrmyat6tJSIckmT2gusprlx0AqtVuoDmaPBoI00F3AYPYM/EOVSpYZuAc wlPVA2L+FypOVn6UPH+LjbB3BNIWXOy2lSi5/p0kBT4tJ2fi4UEVmr7ce0R8GnHWu/wxPH oGea7ik6qAvW7msFR43Da6Fp8I0C2h0= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-159-s_j6uHycNbCQd9e2JrYNNA-1; Mon, 15 May 2023 14:03:42 -0400 X-MC-Unique: s_j6uHycNbCQd9e2JrYNNA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 618F63C0ED41; Mon, 15 May 2023 18:03:41 +0000 (UTC) Received: from tpad.localdomain (ovpn-112-4.gru2.redhat.com [10.97.112.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 04617492B00; Mon, 15 May 2023 18:03:41 +0000 (UTC) Received: by tpad.localdomain (Postfix, from userid 1000) id 54F094161E527; Mon, 15 May 2023 15:02:17 -0300 (-03) Message-ID: <20230515180138.541141182@redhat.com> User-Agent: quilt/0.67 Date: Mon, 15 May 2023 15:00:20 -0300 From: Marcelo Tosatti To: Christoph Lameter Cc: Aaron Tomlin , Frederic Weisbecker , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Russell King , Huacai Chen , Heiko Carstens , x86@kernel.org, Vlastimil Babka , Michal Hocko , Marcelo Tosatti Subject: [PATCH v8 05/13] this_cpu_cmpxchg: x86: switch this_cpu_cmpxchg to locked, add _local function References: <20230515180015.016409657@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Goal is to have vmstat_shepherd to transfer from per-CPU counters to global counters remotely. For this, an atomic this_cpu_cmpxchg is necessary. Following the kernel convention for cmpxchg/cmpxchg_local, change x86's this_cpu_cmpxchg_ helpers to be atomic. and add this_cpu_cmpxchg_local_ helpers which are not atomic. Signed-off-by: Marcelo Tosatti --- Index: linux-vmstat-remote/arch/x86/include/asm/percpu.h =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-vmstat-remote.orig/arch/x86/include/asm/percpu.h +++ linux-vmstat-remote/arch/x86/include/asm/percpu.h @@ -197,11 +197,11 @@ do { \ * cmpxchg has no such implied lock semantics as a result it is much * more efficient for cpu local operations. */ -#define percpu_cmpxchg_op(size, qual, _var, _oval, _nval) \ +#define percpu_cmpxchg_op(size, qual, _var, _oval, _nval, lockp) \ ({ \ __pcpu_type_##size pco_old__ =3D __pcpu_cast_##size(_oval); \ __pcpu_type_##size pco_new__ =3D __pcpu_cast_##size(_nval); \ - asm qual (__pcpu_op2_##size("cmpxchg", "%[nval]", \ + asm qual (__pcpu_op2_##size(lockp "cmpxchg", "%[nval]", \ __percpu_arg([var])) \ : [oval] "+a" (pco_old__), \ [var] "+m" (_var) \ @@ -279,16 +279,20 @@ do { \ #define raw_cpu_add_return_1(pcp, val) percpu_add_return_op(1, , pcp, val) #define raw_cpu_add_return_2(pcp, val) percpu_add_return_op(2, , pcp, val) #define raw_cpu_add_return_4(pcp, val) percpu_add_return_op(4, , pcp, val) -#define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, , pcp, ova= l, nval) -#define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, , pcp, ova= l, nval) -#define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, , pcp, ova= l, nval) +#define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, , pcp, ova= l, nval, "") +#define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, , pcp, ova= l, nval, "") +#define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, , pcp, ova= l, nval, "") =20 #define this_cpu_add_return_1(pcp, val) percpu_add_return_op(1, volatile,= pcp, val) #define this_cpu_add_return_2(pcp, val) percpu_add_return_op(2, volatile,= pcp, val) #define this_cpu_add_return_4(pcp, val) percpu_add_return_op(4, volatile,= pcp, val) -#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, volatile,= pcp, oval, nval) -#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, volatile,= pcp, oval, nval) -#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, volatile,= pcp, oval, nval) +#define this_cpu_cmpxchg_local_1(pcp, oval, nval) percpu_cmpxchg_op(1, vol= atile, pcp, oval, nval, "") +#define this_cpu_cmpxchg_local_2(pcp, oval, nval) percpu_cmpxchg_op(2, vol= atile, pcp, oval, nval, "") +#define this_cpu_cmpxchg_local_4(pcp, oval, nval) percpu_cmpxchg_op(4, vol= atile, pcp, oval, nval, "") + +#define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, volatile,= pcp, oval, nval, LOCK_PREFIX) +#define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, volatile,= pcp, oval, nval, LOCK_PREFIX) +#define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, volatile,= pcp, oval, nval, LOCK_PREFIX) =20 #ifdef CONFIG_X86_CMPXCHG64 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \ @@ -319,16 +323,17 @@ do { \ #define raw_cpu_or_8(pcp, val) percpu_to_op(8, , "or", (pcp), val) #define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(8, , pcp, val) #define raw_cpu_xchg_8(pcp, nval) raw_percpu_xchg_op(pcp, nval) -#define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, ova= l, nval) +#define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, ova= l, nval, "") =20 -#define this_cpu_read_8(pcp) percpu_from_op(8, volatile, "mov", pcp) -#define this_cpu_write_8(pcp, val) percpu_to_op(8, volatile, "mov", (pcp)= , val) -#define this_cpu_add_8(pcp, val) percpu_add_op(8, volatile, (pcp), val) -#define this_cpu_and_8(pcp, val) percpu_to_op(8, volatile, "and", (pcp), = val) -#define this_cpu_or_8(pcp, val) percpu_to_op(8, volatile, "or", (pcp), v= al) -#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(8, volatile,= pcp, val) -#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(8, volatile, pcp, nval) -#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, volatile,= pcp, oval, nval) +#define this_cpu_read_8(pcp) percpu_from_op(8, volatile, "mov", pcp) +#define this_cpu_write_8(pcp, val) percpu_to_op(8, volatile, "mov", (pcp= ), val) +#define this_cpu_add_8(pcp, val) percpu_add_op(8, volatile, (pcp), val) +#define this_cpu_and_8(pcp, val) percpu_to_op(8, volatile, "and", (pcp),= val) +#define this_cpu_or_8(pcp, val) percpu_to_op(8, volatile, "or", (pcp), = val) +#define this_cpu_add_return_8(pcp, val) percpu_add_return_op(8, volatile= , pcp, val) +#define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(8, volatile, pcp, nval) +#define this_cpu_cmpxchg_local_8(pcp, oval, nval) percpu_cmpxchg_op(8, vol= atile, pcp, oval, nval, "") +#define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, volatile= , pcp, oval, nval, LOCK_PREFIX) =20 /* * Pretty complex macro to generate cmpxchg16 instruction. The instruction