From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.57 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793616376; b=niX4rYZqMt7PgnUatsEP46aMZQlG1d3ocNGsvC54xoATCC4xJyc613MmCLYjONzRkojW NU2WcsNqi/SGoTRbeYYtMnYSxg5cc1sabpJuOwLEI43DsyzWNcEHGChV6a1dCxQvYBHez 2QQR6dHv9rjADyMtSEExuLgmm0fxif7RxuvNlKOz6XRm31EnJN63qnobKrrKEm7mLVDvc QyXvnSkWjoj/txMOiwnx0A4Hv1KCa0QvP29TmWxrtbhaPLeWOa3VgNVt2iDPzwpIK3o30 AUEN9db38LLViJP6ynaCgXCf1flMo5tUbQV5tZW+ZEHeHDar49MvzrcIfO4QRDv7yMQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793616376; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding; bh=lxWH9yX4Vl4mKtXKvGkvQaa05rH5ZKTvpkSa847Tggg=; b=EWg5MzCYWb2j8pPKYLRnQjk7ilvYHPnXQJcski5YlQyh5tMhF6c3hgWZJONK4HxZlMm9 w7ulk3GOXbGHlH+JPfDpjfE0IqzeJzqH6+5R4R6hDRH9sJlXCFWBZv4LOr9qNmwVaGBBi ykhlo5Z6ZflnNLT0empBifVEg4jZY1b53QgDIkZu5aGs3iOXAgHoG4Err0/DcWIaVcvDS TGfJGRdJOR4OnMIrhIem1C1sdbjvT0YN245ppCxmq29uSCtMu1xlEjTGVpwLjh3eOii6Q P5w1QDMDzd4Z18ykeBivMzBol+30W+A4yM2ZHLNsxvYskW/0bpSkqSQaBddUgfBioUA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=QYtjFkK8; arc=none smtp.remote-ip=91.218.175.57 Received: from mta0.migadu.com (out-57.mta0.migadu.com [91.218.175.57]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6ABBC606A33E for ; Mon, 2 Nov 2026 10:46:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6ABBC606A33E Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=QYtjFkK8 X-Envelope-To: linux-trace-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=JxbpZPWbvfuRPXcn2jrt5kFSz35KdLS4+oLLTN6f2mY=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793616373; v=1; x=1794221173; b=QYtjFkK8hdk8uOiuA9MT2L7rULzj6PvZ/woEcPBaMxFOK9IyGKXj46if9X4hA8tRUNGFiCjg C7HPhZDSQMLBvF21fWEp+ecXXpS1KL5mc/FMg6wEgebAVov0Exmd0UzZGDodA18lK0sjro9d8Eg Qor1mDKFyw2GLZhqJ7x4CPwc= X-Envelope-To: linux-trace-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 92e7062bea360beb; Mon, 02 Nov 2026 10:46:13 +0000 X-Mizu-Trace-ID: 92e7062bea360beb X-Migadu-Flow: FLOW_OUT Message-ID: <2f272a9b-ea83-4157-8968-0081990cb709@linux.dev> Date: Mon, 2 Nov 2026 18:46:00 +0800 X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 2/6] mm/vmscan: move vmscan tracepoints to a local header To: Baoquan He Cc: Steven Rostedt , Masami Hiramatsu , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Dave Chinner , Mathieu Desnoyers , Muchun Song , Qi Zheng , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baolin Wang , David Hildenbrand , Lorenzo Stoakes , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, "open list:CONTROL GROUP - MEMORY RESOURCE CONTROLLER (MEMCG)" , "open list:BPF [MISC]:Keyword:(?:b|_)bpf(?:b|_)" , Ridong Chen References: <20261031090041.58574-1-ridong.chen@linux.dev> <20261031090041.58574-3-ridong.chen@linux.dev> From: Ridong Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/2/2026 9:37 AM, Baoquan He wrote: > On 10/31/26 at 05:00pm, Ridong Chen wrote: >> From: Ridong Chen >> >> Move include/trace/events/vmscan.h to mm/trace_vmscan.h so that the >> tracepoints can be extended to reference vmscan-internal structures such >> as struct scan_control, which is not visible outside mm/. This mirrors >> what several other subsystems already do with their trace headers (e.g. >> fs/fuse/fuse_trace.h, fs/gfs2/trace_gfs2.h, fs/lockd/trace.h). As they >> do, set TRACE_INCLUDE_PATH to "." and add mm/ to the include path of >> vmscan.o, the only user that defines CREATE_TRACE_POINTS. >> >> No functional change. >> >> Signed-off-by: Ridong Chen >> Reviewed-by: Barry Song >> --- >> MAINTAINERS | 2 ++ >> mm/Makefile | 1 + >> mm/shrinker.c | 2 +- >> include/trace/events/vmscan.h => mm/trace_vmscan.h | 4 ++++ >> mm/vmscan.c | 2 +- >> 5 files changed, 9 insertions(+), 2 deletions(-) >> rename include/trace/events/vmscan.h => mm/trace_vmscan.h (99%) >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index aaf2825ac945..2ad01107fa05 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -17653,6 +17653,7 @@ F: Documentation/admin-guide/mm/multigen_lru.rst >> F: Documentation/mm/multigen_lru.rst >> F: include/linux/mm_inline.h >> F: include/linux/mmzone.h >> +F: mm/trace_vmscan.h >> F: mm/vmscan.c >> F: mm/workingset.c >> >> @@ -17802,6 +17803,7 @@ R: Shakeel Butt >> R: Lorenzo Stoakes >> L: linux-mm@kvack.org >> S: Maintained >> +F: mm/trace_vmscan.h >> F: mm/vmscan.c >> F: mm/workingset.c >> >> diff --git a/mm/Makefile b/mm/Makefile >> index 2a3ec53d62ee..277b97f7f8d7 100644 >> --- a/mm/Makefile >> +++ b/mm/Makefile >> @@ -32,6 +32,7 @@ KCOV_INSTRUMENT_vmstat.o := n >> KCOV_INSTRUMENT_failslab.o := n >> >> CFLAGS_init-mm.o += -Wno-override-init >> +CFLAGS_vmscan.o += -I$(src) > > One nit: > > Does it really need the above line? It affects mm/shrinker.c too, did your > shrinker.o building fail? > > Seems it's redundant because kbuild adds -I$(src) -I$(obj) for every object > in the directory since commit cdd750bfb1f7 ("kbuild: remove 'addtree' and > 'flags' magic for header search paths"). Please correct me if I am > wrong. > Hi Baoquan, Thanks for the review. The line is needed for vmscan.o, and mm/shrinker.c is fine without it, because the two files include trace_vmscan.h in different ways. mm/shrinker.c only does a plain #include "trace_vmscan.h". The lookup starts from mm/, where the header lives, so no -I is needed. mm/vmscan.c defines CREATE_TRACE_POINTS before including the header. In that case , included at the end of trace_vmscan.h, includes the header again to generate the tracepoint definitions: #include TRACE_INCLUDE(TRACE_INCLUDE_FILE) /* -> "./trace_vmscan.h" */ This #include is in include/trace/define_trace.h, so the lookup starts from include/trace/ and only finds the header through -I. Without the flag, vmscan.o fails to build: ./include/trace/define_trace.h:118:42: fatal error: ./trace_vmscan.h: No such file or directory As for cdd750bfb1f7, it doesn't add -I$(src) for every build. kbuild only adds -I$(src) -I$(obj) automatically when building with O= (see "ifdef building_out_of_srctree" in scripts/Makefile.lib). So with O= the line is indeed redundant and vmscan.o builds fine without it, but a plain in-tree "make" fails with the error above. The explicit flag keeps both working. To be honest, I had the same worry at first: I thought every .c file that includes the header would need a Makefile change. That's why v3 used a relative TRACE_INCLUDE_PATH (../../mm) instead. Steven corrected me and pointed out that the proper way is TRACE_INCLUDE_PATH "." plus -I$(src) for the one object that defines CREATE_TRACE_POINTS [1]. That turned out to need only this one line. Thanks again to Steven for that. [1] https://lore.kernel.org/all/20261014124914.21c21559@gandalf.local.home/ > Other than the nit, this patch looks good to me, > > Reviewed-by: Baoquan He > > Thanks. >> >> mmu-y := nommu.o >> mmu-$(CONFIG_MMU) := highmem.o memory.o mincore.o \ >> diff --git a/mm/shrinker.c b/mm/shrinker.c >> index 4fb424e721bc..4fbdade6d2f6 100644 >> --- a/mm/shrinker.c >> +++ b/mm/shrinker.c >> @@ -3,7 +3,7 @@ >> #include >> #include >> #include >> -#include >> +#include "trace_vmscan.h" >> >> #include "internal.h" >> >> diff --git a/include/trace/events/vmscan.h b/mm/trace_vmscan.h >> similarity index 99% >> rename from include/trace/events/vmscan.h >> rename to mm/trace_vmscan.h >> index 8a872990b4be..ad90f0e9bf2e 100644 >> --- a/include/trace/events/vmscan.h >> +++ b/mm/trace_vmscan.h >> @@ -648,4 +648,8 @@ TRACE_EVENT(mm_vmscan_kswapd_clear_hopeless, >> #endif /* _TRACE_VMSCAN_H */ >> >> /* This part must be outside protection */ >> +#undef TRACE_INCLUDE_FILE >> +#undef TRACE_INCLUDE_PATH >> +#define TRACE_INCLUDE_PATH . >> +#define TRACE_INCLUDE_FILE trace_vmscan >> #include >> diff --git a/mm/vmscan.c b/mm/vmscan.c >> index 9959ca158ce8..79d2d614afd0 100644 >> --- a/mm/vmscan.c >> +++ b/mm/vmscan.c >> @@ -71,7 +71,7 @@ >> #include "swap.h" >> >> #define CREATE_TRACE_POINTS >> -#include >> +#include "trace_vmscan.h" >> >> struct scan_control { >> /* How many pages shrink_list() should reclaim */ >> -- >> 2.43.0 >> -- Best regards Ridong