From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH][RFC][BUG] updating the ctime and mtime time stamps in msync() In-Reply-To: Your message of "Wed, 09 Jan 2008 15:50:15 EST." <20080109155015.4d2d4c1d@cuia.boston.redhat.com> From: Valdis.Kletnieks@vt.edu References: <1199728459.26463.11.camel@codedot> <20080109155015.4d2d4c1d@cuia.boston.redhat.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1199912777_3223P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 09 Jan 2008 16:06:17 -0500 Message-ID: <26932.1199912777@turing-police.cc.vt.edu> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: Anton Salikhmetov , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: --==_Exmh_1199912777_3223P Content-Type: text/plain; charset=us-ascii On Wed, 09 Jan 2008 15:50:15 EST, Rik van Riel said: > Could you explain (using short words and simple sentences) what the > exact problem is? > > Eg. > > 1) program mmaps file > 2) program writes to mmaped area > 3) ??? <=== this part, in equally simple words :) > 4) data loss It's like this: Monday 9:04AM: System boots, database server starts up, mmaps file Monday 9:06AM: Database server writes to mmap area, updates mtime/ctime Monday Database server writes to mmap area, no further update.. Monday 11:45PM: Backup sees "file modified 9:06AM, let's back it up" Tuesday 9:00AM-5:00PM: Database server touches it another 5,398 times, no mtime Tuesday 11:45PM: Backup sees "file modified back on Monday, we backed this up.. Wed 9:00AM-5:00PM: More updates, more not touching the mtime Wed 11:45PM: *yawn* It hasn't been touched in 2 days, no sense in backing it up.. Lather, rinse, repeat.... --==_Exmh_1199912777_3223P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.8 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFHhTdJcC3lWbTT17ARAtytAKCxm4JJmxFMV7xD6Lhqad5vNk0sxgCgzb0V m5TQFMylvvkifttlOXMEypE= =9BM7 -----END PGP SIGNATURE----- --==_Exmh_1199912777_3223P-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org