From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 21A0C37FF70; Mon, 23 Feb 2026 23:49:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771890547; cv=none; b=s0h+8NKdMTpaQ/mCzCCsdudaMGrU/ATCSY4vMv/SwHlqZxKSAevAFCRSxEydxN+vNKMoCizXqKfztYFUWMCQi6TS39DtsRkb55W3x7Ph5Rdqj2vOuaWX1H0LxFzumvPMCYrAmpZoIlN85JFZOROIwiH0/i6p6eF/vevzcoqLeUY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771890547; c=relaxed/simple; bh=RE/+s6SOHAE8+brfY1pFPVvbb0I9zwQJhjLk10COkAw=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=PYPXLS6x4JMPciB5pps+UtZK4rPJqCO6rqxd35K2q0UCSjRggzfomaQYSQNODgN5GtvzplPbZIW0OCe8A9DzQ35MA6RSsLusweAX4YMxHD2IOovQN/L7YIYevlfBkueyh99ev3D338raY6UYSVv6tCWzRYZBIyyUYP9x46iSnNA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QlRbcpt2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QlRbcpt2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFAE1C116C6; Mon, 23 Feb 2026 23:49:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771890546; bh=RE/+s6SOHAE8+brfY1pFPVvbb0I9zwQJhjLk10COkAw=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=QlRbcpt2GBitVPAXdaY3B7yTPggzHjGCFeMkTp1kVT3rew3OdRbwV+FwACAWVM13S u53pB5zlFIiIo7v9+1GV7vrjNJEpJcL5PZcsi3LRYTIiYWwt952i9nsANj5Q5i07tN 5fH/+wcK0G1vKL63GnaZAcgD+ujcbg4d7dYOLQ7rrozxPbhy9WtDKHOfjNR97p5tUe 5BJrKd/rKnrVfP/5JRGnjUeyjkwIucrpDPO1HHUBiuUtSl6WT5/G+u6tIlMxVHNcq6 KkEtdK99Cbc9VC2ltKiDQy537TVCXNoC2g1nRUvuu/M1qpC4kulO29l/72EtEUGlis 0bLNqLij1882g== Date: Mon, 23 Feb 2026 15:49:06 -0800 Subject: [PATCH 3/4] fuse4fs: enable memory pressure monitoring with service containers From: "Darrick J. Wong" To: tytso@mit.edu Cc: bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, miklos@szeredi.hu, bernd@bsbernd.com, joannelkoong@gmail.com, neal@gompa.dev Message-ID: <177188746289.3945260.10098153737399667981.stgit@frogsfrogsfrogs> In-Reply-To: <177188746221.3945260.11225620337508354203.stgit@frogsfrogsfrogs> References: <177188746221.3945260.11225620337508354203.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit From: Darrick J. Wong Ask the fuse filesystem service mount helper to open the memory pressure stall files because we cannot open them ourselves. Signed-off-by: "Darrick J. Wong" --- lib/support/psi.h | 9 +++++++ fuse4fs/fuse4fs.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++- lib/support/psi.c | 53 +++++++++++++++++++++++++++++++++++++--- 3 files changed, 128 insertions(+), 5 deletions(-) diff --git a/lib/support/psi.h b/lib/support/psi.h index 675ebeb553da3e..916ebf15d17431 100644 --- a/lib/support/psi.h +++ b/lib/support/psi.h @@ -54,4 +54,13 @@ static inline bool psi_active(struct psi *psi) return psi != NULL; } +char *psi_system_path(enum psi_type type); +ssize_t psi_cgroup_path(enum psi_type type, char *path, size_t pathsize); + +#define PSI_OPEN_FLAGS (O_RDWR | O_NONBLOCK) + +int psi_create_from(enum psi_type type, unsigned int psi_flags, + uint64_t stall_us, uint64_t window_us, uint64_t timeout_us, + int *system_fd, int *cgroup_fd, struct psi **psip); + #endif /* __PSI_H__ */ diff --git a/fuse4fs/fuse4fs.c b/fuse4fs/fuse4fs.c index 87b17491beae13..4d48521fa8f763 100644 --- a/fuse4fs/fuse4fs.c +++ b/fuse4fs/fuse4fs.c @@ -327,6 +327,8 @@ struct fuse4fs { char *svc_cmdline; int bdev_fd; int fusedev_fd; + int psi_sys_mem_fd; + int psi_cgroup_mem_fd; #endif struct psi *mem_psi; struct psi_handler *mem_psi_handler; @@ -939,8 +941,16 @@ static int fuse4fs_psi_config(struct fuse4fs *ff) * Activate when there are memory stalls for 200ms every 2s; or * 5min goes by. Unprivileged processes can only use 2s windows. */ - err = psi_create(PSI_MEMORY, PSI_TRIM_HEAP, 20100, 2000000, - 5 * 60 * 1000000, &ff->mem_psi); +#ifdef HAVE_FUSE_SERVICE + if (fuse4fs_is_service(ff)) + err = psi_create_from(PSI_MEMORY, PSI_TRIM_HEAP, 202002, + 2000000, 5 * 60 * 1000000, + &ff->psi_sys_mem_fd, + &ff->psi_cgroup_mem_fd, &ff->mem_psi); + else +#endif + err = psi_create(PSI_MEMORY, PSI_TRIM_HEAP, 202002, 2000000, + 5 * 60 * 1000000, &ff->mem_psi); if (err) { switch (errno) { case ENOENT: @@ -1564,6 +1574,14 @@ static int fuse4fs_service_finish(struct fuse4fs *ff, int ret) close(ff->bdev_fd); ff->bdev_fd = -1; + if (ff->psi_sys_mem_fd >= 0) + close(ff->psi_sys_mem_fd); + ff->psi_sys_mem_fd = -1; + + if (ff->psi_cgroup_mem_fd >= 0) + close(ff->psi_cgroup_mem_fd); + ff->psi_cgroup_mem_fd = -1; + /* * If we're being run as a service, the return code must fit the LSB * init script action error guidelines, which is to say that we @@ -1585,6 +1603,49 @@ static int fuse4fs_service_finish(struct fuse4fs *ff, int ret) return EXIT_SUCCESS; } +/* Open PSI control files */ +static int fuse_service_open_psi_controls(struct fuse4fs *ff) +{ + const char *psifile = psi_system_path(PSI_MEMORY); + char cgpath[PATH_MAX]; + ssize_t cgpathlen; + int ret; + + ret = fuse_service_request_file(ff->service, psifile, PSI_OPEN_FLAGS, + 0, 0); + if (ret) + return ret; + + ret = fuse_service_receive_file(ff->service, psifile, + &ff->psi_sys_mem_fd); + if (ret) + return ret; + if (ff->psi_sys_mem_fd < 0) + err_printf(ff, "%s %s: %s.\n", + _("opening system memory pressure monitor"), + psifile, strerror(errno)); + + cgpathlen = psi_cgroup_path(PSI_MEMORY, cgpath, sizeof(cgpath)); + if (!cgpathlen || cgpathlen >= sizeof(cgpath)) + return 0; + + ret = fuse_service_request_file(ff->service, cgpath, PSI_OPEN_FLAGS, + 0, 0); + if (ret) + return ret; + + ret = fuse_service_receive_file(ff->service, cgpath, + &ff->psi_cgroup_mem_fd); + if (ret) + return ret; + if (ff->psi_cgroup_mem_fd < 0) + err_printf(ff, "%s %s: %s.\n", + _("opening cgroup memory pressure monitor"), + cgpath, strerror(errno)); + + return 0; +} + static int fuse4fs_service_get_config(struct fuse4fs *ff) { double deadline = init_deadline(FUSE4FS_OPEN_TIMEOUT); @@ -1620,6 +1681,10 @@ static int fuse4fs_service_get_config(struct fuse4fs *ff) return -1; } + ret = fuse_service_open_psi_controls(ff); + if (ret) + return ret; + ret = fuse_service_finish_file_requests(ff->service); if (ret) return ret; @@ -8581,6 +8646,8 @@ int main(int argc, char *argv[]) #ifdef HAVE_FUSE_SERVICE .bdev_fd = -1, .fusedev_fd = -1, + .psi_sys_mem_fd = -1, + .psi_cgroup_mem_fd = -1, #endif }; errcode_t err; diff --git a/lib/support/psi.c b/lib/support/psi.c index 26ce6ee1985641..531ae935701edf 100644 --- a/lib/support/psi.c +++ b/lib/support/psi.c @@ -54,7 +54,7 @@ struct psi { enum psi_state state; }; -static const char *psi_system_path(enum psi_type type) +char *psi_system_path(enum psi_type type) { switch (type) { case PSI_MEMORY: @@ -300,7 +300,7 @@ void psi_destroy(struct psi **psip) static int psi_open_control(const char *path) { - return open(path, O_RDWR | O_NONBLOCK); + return open(path, PSI_OPEN_FLAGS); } static void psi_open_system_control(struct psi *psi) @@ -309,7 +309,7 @@ static void psi_open_system_control(struct psi *psi) psi->system_fd = psi_open_control(psi_system_path(psi->type)); } -static ssize_t psi_cgroup_path(enum psi_type type, char *path, size_t pathsize) +ssize_t psi_cgroup_path(enum psi_type type, char *path, size_t pathsize) { char cgpath[PATH_MAX]; char *p = cgpath; @@ -485,6 +485,53 @@ int psi_create(enum psi_type type, unsigned int psi_flags, uint64_t stall_us, return -1; } +/* + * Same as psi_create, but you can specify the whole-system and per-cgroup + * monitoring fds. + */ +int psi_create_from(enum psi_type type, unsigned int psi_flags, + uint64_t stall_us, uint64_t window_us, uint64_t timeout_us, + int *system_fd, int *cgroup_fd, struct psi **psip) +{ + struct psi *psi; + int ret; + + if (psi_flags & ~PSI_FLAGS) { + errno = EINVAL; + return -1; + } + + psi = psi_alloc(type, psi_flags, timeout_us); + if (!psi) + return -1; + + psi->system_fd = *system_fd; + psi->cgroup_fd = *cgroup_fd; + + *system_fd = -1; + *cgroup_fd = -1; + + if (psi->system_fd < 0 && psi->cgroup_fd < 0 && !psi->timeout_us) { + errno = ENOENT; + goto out_fds; + } + + ret = psi_config_fd(psi, psi->system_fd, stall_us, window_us); + if (ret) + goto out_fds; + + ret = psi_config_fd(psi, psi->cgroup_fd, stall_us, window_us); + if (ret) + goto out_fds; + + *psip = psi; + return 0; + +out_fds: + psi_destroy(&psi); + return -1; +} + /* Start monitoring for resource pressure stalls */ int psi_start_thread(struct psi *psi) {