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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8FA2CCA479 for ; Tue, 28 Jun 2022 09:59:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245466AbiF1J7s (ORCPT ); Tue, 28 Jun 2022 05:59:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344617AbiF1J7W (ORCPT ); Tue, 28 Jun 2022 05:59:22 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05EDD2ED6A for ; Tue, 28 Jun 2022 02:59:16 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-3177608c4a5so99088547b3.14 for ; Tue, 28 Jun 2022 02:59:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Ar0tQaDtQRVxSK1L64O5LGBBBeYgKP9H/0S8vYb7eY0=; b=QDaFAZbFppsXaGKVqzfkonMpccyr1cbOroDVbmeHjzV5Y5PKhzNM4NZ4HtvM2w6F5X qS3uJLF/cnyo+Y9dbZmY4O4l/xiGaBWPD8yy9soRQ0MVn8obJY7/4CupDFChWXOS0d4M g9Z7akfK1xChH19AZzJG+bP+GG6rojDxrnmRwxICTwa939HvKZYiSQWXLQK58qOGEFJ6 07lg8mVua/7rqrL/A4yl+GSFL7zEk/c1UsOEDsSQgQ5QaXVHZByNl65yUJvgGyM8f5uI D49G3Zf6ZhA+eiMN2aMH510qgfvOXQCX3lEL9qzEBWpg1nt8B7Xc+oXqvgghD5d51qlK 3LPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Ar0tQaDtQRVxSK1L64O5LGBBBeYgKP9H/0S8vYb7eY0=; b=kF1Y/ynhqcFawBbnwlepqumargIsXzWYbLeWeEo+xaRgQQJZe2ZnDFXMERb/WuTev1 8AMnW2+EYUzHq1If789lJoD+00j1jUsFItxBDCbLAH9Z/QSO3ofTe+hmI+RZtGNteuB5 vLrD1CEWZRrVYKIlHC9pv6zsNdP/wnRfFmkAhAACYFZsriM52A9dbZN0AeSByuYOZQpH wZZKZZqCWN4K4D3Tz5P6a8hkiOs9Zq2bsm78nZGkvVRLRfwkZOxbCKd5NIH0y7GEVNdr MzvSy5l7ImOLleT118KnHZTo9NAbcnXPTx6kcJh1W95PuQG35VgPrVxdp9CM2xDFWTpc E05w== X-Gm-Message-State: AJIora8oEeRkR+Dr/AJXXBHlt5UBuRiGn49J5wahJQhgTT9lO2xOEtLn r4vzW7AjWHhXC+XXY7OXiy9g1I+DBw== X-Google-Smtp-Source: AGRyM1tI+zmY9bXD9lPsRaWsu6mvsAtKuZuIuC7/08NiJKMQvXlU/prcjNa4TCejWigh16YxBHUIR7IxOg== X-Received: from elver.muc.corp.google.com ([2a00:79e0:9c:201:3496:744e:315a:b41b]) (user=elver job=sendgmr) by 2002:a81:6603:0:b0:317:8d2f:e255 with SMTP id a3-20020a816603000000b003178d2fe255mr20169767ywc.166.1656410355202; Tue, 28 Jun 2022 02:59:15 -0700 (PDT) Date: Tue, 28 Jun 2022 11:58:26 +0200 In-Reply-To: <20220628095833.2579903-1-elver@google.com> Message-Id: <20220628095833.2579903-7-elver@google.com> Mime-Version: 1.0 References: <20220628095833.2579903-1-elver@google.com> X-Mailer: git-send-email 2.37.0.rc0.161.g10f37bed90-goog Subject: [PATCH v2 06/13] perf/hw_breakpoint: Make hw_breakpoint_weight() inlinable From: Marco Elver To: elver@google.com, Peter Zijlstra , Frederic Weisbecker , Ingo Molnar Cc: Thomas Gleixner , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Dmitry Vyukov , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-perf-users@vger.kernel.org, x86@kernel.org, linux-sh@vger.kernel.org, kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Due to being a __weak function, hw_breakpoint_weight() will cause the compiler to always emit a call to it. This generates unnecessarily bad code (register spills etc.) for no good reason; in fact it appears in profiles of `perf bench -r 100 breakpoint thread -b 4 -p 128 -t 512`: ... 0.70% [kernel] [k] hw_breakpoint_weight ... While a small percentage, no architecture defines its own hw_breakpoint_weight() nor are there users outside hw_breakpoint.c, which makes the fact it is currently __weak a poor choice. Change hw_breakpoint_weight()'s definition to follow a similar protocol to hw_breakpoint_slots(), such that if defines hw_breakpoint_weight(), we'll use it instead. The result is that it is inlined and no longer shows up in profiles. Signed-off-by: Marco Elver --- include/linux/hw_breakpoint.h | 1 - kernel/events/hw_breakpoint.c | 4 +++- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/include/linux/hw_breakpoint.h b/include/linux/hw_breakpoint.h index 78dd7035d1e5..9fa3547acd87 100644 --- a/include/linux/hw_breakpoint.h +++ b/include/linux/hw_breakpoint.h @@ -79,7 +79,6 @@ extern int dbg_reserve_bp_slot(struct perf_event *bp); extern int dbg_release_bp_slot(struct perf_event *bp); extern int reserve_bp_slot(struct perf_event *bp); extern void release_bp_slot(struct perf_event *bp); -int hw_breakpoint_weight(struct perf_event *bp); int arch_reserve_bp_slot(struct perf_event *bp); void arch_release_bp_slot(struct perf_event *bp); void arch_unregister_hw_breakpoint(struct perf_event *bp); diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index a089302ddf59..a124786e3ade 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -124,10 +124,12 @@ static __init int init_breakpoint_slots(void) } #endif -__weak int hw_breakpoint_weight(struct perf_event *bp) +#ifndef hw_breakpoint_weight +static inline int hw_breakpoint_weight(struct perf_event *bp) { return 1; } +#endif static inline enum bp_type_idx find_slot_idx(u64 bp_type) { -- 2.37.0.rc0.161.g10f37bed90-goog