{"id":2221804,"url":"http://patchwork.ozlabs.org/api/patches/2221804/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260410120318.121043259@kernel.org/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/","list_archive_url":"https://lore.kernel.org/linuxppc-dev/","list_archive_url_format":"https://lore.kernel.org/linuxppc-dev/{}/","commit_url_format":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}"},"msgid":"<20260410120318.121043259@kernel.org>","list_archive_url":"https://lore.kernel.org/linuxppc-dev/20260410120318.121043259@kernel.org/","date":"2026-04-10T12:19:08","name":"[08/38] x86/tsc: Use rdtsc() instead of get_cycles()","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"d61d821fd3567ca3b8d1aa5189513de1ec3c4a85","submitter":{"id":92397,"url":"http://patchwork.ozlabs.org/api/people/92397/?format=json","name":"Thomas Gleixner","email":"tglx@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260410120318.121043259@kernel.org/mbox/","series":[{"id":499449,"url":"http://patchwork.ozlabs.org/api/series/499449/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=499449","date":"2026-04-10T12:18:27","name":"treewide: Cleanup LATCH, CLOCK_TICK_RATE and get_cycles() [ab]use","version":1,"mbox":"http://patchwork.ozlabs.org/series/499449/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2221804/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2221804/checks/","tags":{},"related":[],"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=YwhpP/sf;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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charset=UTF-8","cc":"Arnd Bergmann ,\n x86@kernel.org,\n Lu Baolu ,\n iommu@lists.linux.dev,\n Michael Grzeschik ,\n netdev@vger.kernel.org,\n linux-wireless@vger.kernel.org,\n Herbert Xu ,\n linux-crypto@vger.kernel.org,\n Vlastimil Babka ,\n linux-mm@kvack.org,\n David Woodhouse ,\n Bernie Thompson ,\n linux-fbdev@vger.kernel.org,\n \"Theodore Tso\" ,\n linux-ext4@vger.kernel.org,\n Andrew Morton ,\n Uladzislau Rezki ,\n Marco Elver ,\n Dmitry Vyukov ,\n kasan-dev@googlegroups.com,\n Andrey Ryabinin ,\n Thomas Sailer ,\n linux-hams@vger.kernel.org,\n \"Jason A. Donenfeld\" ,\n Richard Henderson ,\n linux-alpha@vger.kernel.org,\n Russell King ,\n linux-arm-kernel@lists.infradead.org,\n Catalin Marinas ,\n Huacai Chen ,\n loongarch@lists.linux.dev,\n Geert Uytterhoeven ,\n linux-m68k@lists.linux-m68k.org,\n Dinh Nguyen ,\n Jonas Bonn ,\n linux-openrisc@vger.kernel.org,\n Helge Deller ,\n linux-parisc@vger.kernel.org,\n Michael Ellerman ,\n linuxppc-dev@lists.ozlabs.org,\n Paul Walmsley ,\n linux-riscv@lists.infradead.org,\n Heiko Carstens ,\n linux-s390@vger.kernel.org,\n \"David S. Miller\" ,\n sparclinux@vger.kernel.org","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,\n\tDKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS\n\tautolearn=disabled version=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"This code knows that TSC is available so there is no point to use the TSC\nfeature guarded get_cycles().\n\nNo functional change.\n\nSigned-off-by: Thomas Gleixner \n---\n arch/x86/kernel/tsc.c | 12 ++++++------\n 1 file changed, 6 insertions(+), 6 deletions(-)","diff":"--- a/arch/x86/kernel/tsc.c\n+++ b/arch/x86/kernel/tsc.c\n@@ -371,12 +371,12 @@ static u64 tsc_read_refs(u64 *p, int hpe\n \tint i;\n \n \tfor (i = 0; i < MAX_RETRIES; i++) {\n-\t\tt1 = get_cycles();\n+\t\tt1 = rdtsc();\n \t\tif (hpet)\n \t\t\t*p = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;\n \t\telse\n \t\t\t*p = acpi_pm_read_early();\n-\t\tt2 = get_cycles();\n+\t\tt2 = rdtsc();\n \t\tif ((t2 - t1) < thresh)\n \t\t\treturn t2;\n \t}\n@@ -468,13 +468,13 @@ static unsigned long pit_calibrate_tsc(u\n \toutb(latch & 0xff, 0x42);\n \toutb(latch >> 8, 0x42);\n \n-\ttsc = t1 = t2 = get_cycles();\n+\ttsc = t1 = t2 = rdtsc();\n \n \tpitcnt = 0;\n \ttscmax = 0;\n \ttscmin = ULONG_MAX;\n \twhile ((inb(0x61) & 0x20) == 0) {\n-\t\tt2 = get_cycles();\n+\t\tt2 = rdtsc();\n \t\tdelta = t2 - tsc;\n \t\ttsc = t2;\n \t\tif ((unsigned long) delta < tscmin)\n@@ -553,9 +553,9 @@ static inline int pit_expect_msb(unsigne\n \t\tif (!pit_verify_msb(val))\n \t\t\tbreak;\n \t\tprev_tsc = tsc;\n-\t\ttsc = get_cycles();\n+\t\ttsc = rdtsc();\n \t}\n-\t*deltap = get_cycles() - prev_tsc;\n+\t*deltap = rdtsc() - prev_tsc;\n \t*tscp = tsc;\n \n \t/*\n","prefixes":["08/38"]}