From nobody Tue May 20 09:08:38 2025 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4b1pd24lh2z5w4c3; Tue, 20 May 2025 09:08:38 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4b1pd241tPz43cH; Tue, 20 May 2025 09:08:38 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1747732118; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7/12tAPEYj8k5ZLBO5mbS+8MePBEFiyNDEi/SD4qFWM=; b=bR20VYgeo/OoMboz1EgQnKnuzn7HO5EQAn0fBxa00Sw+q7+1pyGmYIJUGRpcaz3rLC1xuA xcZ4+ZfFrhBF3pKUV79VWefxrquwebNlG3jI3LW+RoWLnIiYcjX+VqQFhCpGY+a1Bo/mEc N5ARdGEs3axMp9j926mk3/GuPHCb4tLe65MZYQRy6+81FFBM5u3GQbdra0geJtAvzR+Kg8 pXBUN6JVZJEXQbjXyw7P0hp2ARC4kqsYVrX4QkV2BuYaJPv4x30nHMhjBOeW7TlD6ta8MX +tv1qUBKCDRzN+R2ZKLls+XqrmrB64pO90sIWCvkxRd5gSiy2AGgtE/vaE58KQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1747732118; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7/12tAPEYj8k5ZLBO5mbS+8MePBEFiyNDEi/SD4qFWM=; b=LXJ5O1aV1dWxqf6c7QjWS09P9wHJPrVfEhz7SOQlFNRFqi7IEl/FcXmOOsFoort5PevJ5Y bzMR5TCLbJY1oq1hFu9cTKCgMibjDSlvZ047ztfZC8XDgT5zmI/LxnKRlnKsCRnK3RQvMQ PGFy/gKp53gqqRgQjCTQpq1di+OvVWAEek07xBig3bOmQXI75qDx/t/x4QTDYHmwCv0nsR PWzlguu0xO/hOKGwAK+8wQbecVin2S0RI7ax1r1WjTmaCOZAAijppTNkHWUPbGB2aRw536 uPFVz7VDUMqbVNFMGL2QBGWzvxsrmi6q2Y8rQ3lydIgVDRYW2CZXK1g6hixYfA== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1747732118; a=rsa-sha256; cv=none; b=A75bhPeoULabzGBq55siXfFGP7oajpnQtSgMWV4pCcq3YUGBH7YYxFPGUHauO16pwkt1Ii XmsicXw9US+L7GUqaZPah1hfHCn9m/pf2Bs7bhpJMiF8Nzca4onNs//nCP5yo0I4f7gUyO 16Q09OB6Pk6hRf5CWMC58yQrEQfd5KNKEJ3YjY+Q2Vrocz51Z0GcuNqbYEm4gf5apZcwok QwuuIgaXpKW0zuXb5RmSIdnkHUdgHoZAAvTrcl160prat4rHgxJEp0o3nnyVmZMzciKCGn OihP3ShhCaj+ybj52Jg0kvhXiDB83/EVcmPJpa4+rCsES0YHcMp2mUv5mRLDFQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4b1pd23LhSzkZ8; Tue, 20 May 2025 09:08:38 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 54K98ccw000814; Tue, 20 May 2025 09:08:38 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 54K98cSs000811; Tue, 20 May 2025 09:08:38 GMT (envelope-from git) Date: Tue, 20 May 2025 09:08:38 GMT Message-Id: <202505200908.54K98cSs000811@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Olivier Certner Subject: git: e7d4e52eafb0 - stable/14 - Compute 'maxproc'/'maxfiles' from memory amount; Expand/fix comments List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: olce X-Git-Repository: src X-Git-Refname: refs/heads/stable/14 X-Git-Reftype: branch X-Git-Commit: e7d4e52eafb016707ef3dd3b778d76db280c06a4 Auto-Submitted: auto-generated The branch stable/14 has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=e7d4e52eafb016707ef3dd3b778d76db280c06a4 commit e7d4e52eafb016707ef3dd3b778d76db280c06a4 Author: Olivier Certner AuthorDate: 2025-05-02 12:47:32 +0000 Commit: Olivier Certner CommitDate: 2025-05-20 09:05:33 +0000 Compute 'maxproc'/'maxfiles' from memory amount; Expand/fix comments Change the formulae so that 'maxproc' and 'maxfiles' are computed based on the physical memory amount, and not the corresponding number of pages. Make sure that the practical results are unchanged for all architectures (which is possible since all have 4096 as their PAGE_SIZE). Despite this, we do this change to make it clearer how many units of these values are computed per MB, which is easier on readers. Change the comments accordingly and expand them to indicate which parts of the computations are actually not used by default. In passing, fix the comments about default values and limits for 'maxfiles' (they were off). No functional change (intended). MFC after: 3 days Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D50124 (cherry picked from commit 73f9251c0b52ac0bfb2f2baff27493d6bae216f6) --- sys/kern/subr_param.c | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c index 67dc10213a70..36009a5c1be1 100644 --- a/sys/kern/subr_param.c +++ b/sys/kern/subr_param.c @@ -70,13 +70,14 @@ # define HZ_VM HZ # endif #endif +/* See the comments in init_param2() for these. */ #define NPROC (20 + 16 * maxusers) -#ifndef NBUF -#define NBUF 0 -#endif #ifndef MAXFILES #define MAXFILES (40 + 32 * maxusers) #endif +#ifndef NBUF +#define NBUF 0 +#endif static int sysctl_kern_vm_guest(SYSCTL_HANDLER_ARGS); @@ -276,13 +277,14 @@ init_param1(void) void init_param2(long physpages) { + long maxproc_clamp, maxfiles_clamp; TSENTER(); /* Base parameters */ maxusers = MAXUSERS; TUNABLE_INT_FETCH("kern.maxusers", &maxusers); if (maxusers == 0) { - maxusers = physpages / (2 * 1024 * 1024 / PAGE_SIZE); + maxusers = pgtok(physpages) / (2 * 1024); if (maxusers < 32) maxusers = 32; #ifdef VM_MAX_AUTOTUNE_MAXUSERS @@ -291,35 +293,43 @@ init_param2(long physpages) #endif /* * Scales down the function in which maxusers grows once - * we hit 384. + * we hit 384 (16MB to get a new "user"). */ if (maxusers > 384) maxusers = 384 + ((maxusers - 384) / 8); } /* - * The following can be overridden after boot via sysctl. Note: - * unless overridden, these macros are ultimately based on maxusers. - * Limit maxproc so that kmap entries cannot be exhausted by - * processes. + * The following can be overridden after boot via sysctl. Note: unless + * overridden, these macros are ultimately based on 'maxusers'. Limit + * maxproc so that kmap entries cannot be exhausted by processes. The + * default for 'maxproc' linearly scales as 16 times 'maxusers' (so, + * linearly with 8 processes per MB up to 768MB, then 1 process per MB; + * overridable by a tunable), and is then clamped at 21 + 1/3 processes + * per MB (which never happens by default as long as physical memory is + * > ~1.5MB). */ maxproc = NPROC; TUNABLE_INT_FETCH("kern.maxproc", &maxproc); - if (maxproc > (physpages / 12)) - maxproc = physpages / 12; + maxproc_clamp = pgtok(physpages) / (3 * 1024 / 64); + if (maxproc > maxproc_clamp) + maxproc = maxproc_clamp; if (maxproc > pid_max) maxproc = pid_max; maxprocperuid = (maxproc * 9) / 10; /* - * The default limit for maxfiles is 1/12 of the number of - * physical page but not less than 16 times maxusers. - * At most it can be 1/6 the number of physical pages. + * 'maxfiles' by default is set to 32 files per MB (overridable by + * a tunable), and is then clamped at 64 files per MB (which thus never + * happens by default). (The default MAXFILES is for all practical + * purposes not used, as it gives a lower value than 32 files per MB as + * soon as there is more than ~2.5MB of memory.) */ - maxfiles = imax(MAXFILES, physpages / 8); + maxfiles = imax(MAXFILES, pgtok(physpages) / (1024 / 32)); TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles); - if (maxfiles > (physpages / 4)) - maxfiles = physpages / 4; + maxfiles_clamp = pgtok(physpages) / (1024 / 64); + if (maxfiles > maxfiles_clamp) + maxfiles = maxfiles_clamp; maxfilesperproc = (maxfiles / 10) * 9; TUNABLE_INT_FETCH("kern.maxfilesperproc", &maxfilesperproc);